We've got a thread about tents, so let's talk about sleeping bags
I've seen a lot of posts about all the different bags people have in their packs, and a few posts about multi-layer systems that are smaller than the average rolled bag yet suitable for just about any situation.
So what do you sleep in when you camp?

I always carry an older, thick, Coleman sleeping bag made for approx 30 degree weather. I also always carry a Falsa blanket (bought at a truck stop). I now also carry an inflatable mattress (cheap), a small tarp (cheap), and a foam sleeping pad. This is my basic preference for camping out in Louisiana most of the time.

In colder weather, I will have the tarp down as a floor and folded back into a lean-to. The air mattress under the foam sleeping pad, with the sleeping bag on top of it. I'll have a Falsa blanket, sheet, Falsa blanket, and sheet on top of the sleeping bag with me inside of the bag. This provides great insulation and thus, great sleeping!

If I am using a tent, then I'll use the tarp as a ground sheet for the tent.

I roll up the sleeping bag, Falsa blankets and sheets, lengthwise. I then roll the sleeping bag up inside of the tarp, and strap this under the backpack top flap and tie the ends to each side of the backpack. I roll up the foam pad and strap it to the bottom of the backpack. If I am carrying a tent, I'll strap it to the bottom of the backpack alongside of the foam pad.

I can carry less layers if the weather is warm and I can carry more layers if the weather is cold.

I carry a pretty large military style sleeping bag + pad. It is bulkier than I'd have preferred ideally but warm enough for temperatures down to about freezing. I should point out though that I never sleep in a tent so I need a slightly warmer sleeping bag.

A friend of mine just brings along two light sleeping bags when the weather gets colder. Seems to work really well putting one bag inside the other because of the extra insulating layer of air trapped in between.

I carry pretty light. I am a warm sleeper and use a Big Agnes Yampa +40 bag. I also use the Big Agnes inflatable sleep pad. With Big Agnes bags the pad slides into a sleeve in the bottom of the bag for two reasons, 1) you don't slide off the pad, 2) there is less loft put into the bottom of the bag to save weight.

If its colder than 40F then I put on more layers of clothes but like I said I am a warm sleeper. I could sleep in long johns, bacalava and wool socks in that bag and be warm to 20F.

In summers with temps guaranteed over 50F I just carry my inflatable a closed cell foam mattress and my 'woobie' (military poncho)

I use a Western Mountain Bristlecone MF (ambient down to -10 degrees), a military issue poncho liner from US Calvary for hot nights. Also I have a Rivers West H2P Artillery Blanket that benjammin recommended for a little cooler nights but I use it mostly as a ground pad so if the temps start dropping it can be used as a blanket. Definitely a hard core blanket.


Western Mountaineering


Poncho liner
NSN: 8405-00-889-3683

River West

I'm not sure how versatile it is, but here's what I use:

Above roughly 40F:
Marmot Trestles 15 degree sleeping bag (from Campmor.com)
Exped 9DLX Synmat

Below roughly 40F:
Cabelas Summit -20 degree sleeping bag
Wool Socks - or else my feet get cold
Loose synthetic stocking cap
Exped 9DLX Synmat
Cheap closed-cell foam pad under Synmat

Backpacking: TNF Big Kazoo down bag, closed cell foam pad, Bibler Bivy, fleece jacket for pillow. Spring and Fall - add lightweight polypro, beanie and socks.

BOB: Just Heetsheets and clothes, silnylon tarp in FL Summer, add cheap, heavily compressed mummy bag for cooler months.

DMAT deployments: Army cot and sleeping bag system, or full twin size air bed, and memory foam pillow.

Jeff

Backpacking: My system is not too versatile, other than having several different bags at home.

Slumberjack Everest: I've had this for 17 years. It's a 3-season bag, but a bit hot in the summer unless I leave it completely unzipped. In the winter months I augment it by slipping another bag inside - a cheap fleece-type sleeping bag or my newer lightweight bag below.

???: I've got a light weight, very compressible bag that I picked up on sale this summer. Definitely a summer-bag only, but it's light and small. Can't remember the make or model right now.

Cabela's Adam and Eve Bag: For car camping with the family. Makes snuggling with the wife so much easier.

BOB: Adventure Medical Kits Thermo-Lite 2.0 Bivvies for each member of the family. (I have smaller children, so not everyone is ready to lug a bag around, so the BOB has to fit in two bags - one for a parent and one for the oldest child). Perhaps as the children get older and can carry more we will add heavier duty bags).

As far as pads go, for years I just used the cheep closed cell foam pads. The last few years I decided I'm getting softer. I now have (in addition to the old foam pads) a Therm-a-rest ProLite 4, as well as a Cabela's pad of similar construction. For car camping I take a queen size air mattress (for the Adam and Eve bag). For long term camping with the Scouts I take a Cabela's cot.

For non-vehicle bug out- AMK Bivy bags for the two of us and the 2 person heatsheet. Ridge rest closed cell pads. Tarp and Cord for either shelter or ground. I also have 2 foreign military emergency blankets, thick silver, polyester, I think, I got them years ago from SG but have never seen them since. Kinda overkill but everything light weight enough to accommodate.

For backpacking- Thermo-lite Bivy bags and fleece sleeping bags. Ridge rest pads and Rei Camp Dome Tent w/footprint.

i was using a down bag on canoe trips for several years but i found that after a couple weeks on the trail they lost their loft...it was like sleeping between sheets of cardboard..the air is so humid around all those lake that even hanging the bag up to air out did not help much..now i just use a middle price poly fill bag and if it's cold..below 40's at nite..i just wear my poly fluff soxs..pants..shirt..
the Thermarest two inch pad is a life saver for older guys like me....i think where i was going with this is where do you plan to use the bag??..if i was out West i would go back to a down bag for the cold-dry climate..

I was using a Coleman (2-ton rectangular bag) and my wife had a WalMart bag (what are they? Ozark Trails or something?). I recently upgraded to a new Coleman Ultimate (MUCH better), so my wife will take the old one and my daughter will get the smaller WalMart bag.

I pack depending on the weather, and how much I feel like carrying.

Bags (one of these):
Western Mountaineering Iroquois (38 degrees, down)- I probably use this 70% of the time.
Western Mountaineering Antelope Super Microfiber (5 degrees, down) - My winter bag.
Sierra Designs Wild Bill (20 degrees, synthetic) Only carried if it's going to rain all week, like in the Smokies in springtime.
Eastern Mountain Sports Alpine (40 degrees, synthetic) Same as above, and also used for canoe trips.

Pads (one of these):
Thermarest Pro 4, full length self-inflating pad
Ridgerest Deluxe, full-length foam
Ridgerest shorty, 3/4 length foam

Bivy:
I'll carry an Equinox bivy if I'm sleeping under a tarp or might use a trail shelter along the AT. It obviates the need for a groundcloth, and the breathable fabric does a nice job of adding warmth and keeping off any rain spay if it's really coming down.

My shelter/sleeping bag is a hammock:

Hennessy Hammock
JRB tarp
JRB three season quilts (below hammock & top quilt)

I've never slept better - warm, comfortable, light gear.
My tent is only used now for areas with no trees which is not my typical hike.

I have a picture on WhiteBlaze:
http://whiteblaze.net/forum/vbg/showimage.php?i=12187

Non-winter: a MontBell Ultralight Stretch Down Hugger rated to 32°F or a GoLite Ultra Quilt inside of an ultralight bivy. Use a 2/3 length Thermarest ultralight pad underneath. Total weight just under 2 pounds for the first setup, 2.5 for the second.

Winter: a Western Mountaineering Antelope (-5°F) or Valandre La Fayette (same rating, though I pushed it to -14°F and was still perfectly warm inside a tent), over an Insulmat insultated lightweight inflatable pad topped by 1/4" blue closed cell foam. Total weight under four pounds for everything.

For late spring, summer, and early fall, I have a Western Mountaineering SummerLite +32F down bag. It weighs just over a pound and compresses down to a very small package which is convenient since I can do overnight trips just using a day pack. There are lighter bags, but the SummerLite has a full length zipper, which makes it more flexible. In hot weather, I unzip the bag and use it like a comforter. With the SummerLite, I use a Thermarest ProLite 3 (1" thick) short (short = ~3/4 length). Thermarests are self inflating open cell foam mattresses. I've been using them for about 20 years. I sleep well on the 1.5" thick models, and I'm a side sleeper. I sleep well on the 1.0" thick models if I'm on soft ground. They do take some playing with to get the right air pressure for maximum comfort. The ProLite 3 is very light and compact but does have problems with getting punctured if one sleeps out under the stars with only a light plastic sheet as a ground cloth. No puncture problems when used with a tent or thicker ground cloth. The Prolite 3 is a little thin in terms of padding when sleeping on a hard surface but is quite sufficient on soft ground, pine needles, etc.

For early spring or late fall when things are considerably cooler, I use a Mountain Hardware Phantom 15 +15F down bag. It weighs just under two pounds and compresses down to a relatively small package, although not as small as my Summerlite. Great bag. I've used it for snow camping in good weather. With the Phantom 15, I use a Thermarest ProLite 4 (1.5" thick) regular (regular = full length).

For winter, I use a North Face Snowshoe 0F synthetic bag. The snowshoe does not compress well and weighs just under 3.5 lbs. This bag is a bit of pain since it doesn't compress well which forces me to carry a larger (and therefore heavier) pack, but dang is it warm. I've actually been too hot on many nights when my hiking partners were too cold, and I am not a warm sleeper. With the Snowshoe, I use a Thermarest ProLite 4 regular with a full length Ridgerest (closed cell foam pad) underneath the Thermarest. I sleep well on just a 1.5" Thermarest alone, but when I put a Ridgerest underneath, it's almost as comfortable as my bed at home (although not as wide) .

OK, yep, I've got three bags, not exactly the cheapest way to go. However, I spread the cost out some, buying the first bag in 2000 and the last bag in 2007, and the three bags pretty well cover everything I like to do. I also bought one of the bags off eBay which saved me some $$'s.

HJ

Hello it has been a long time since I have posted("forgive me moderators for i have not...)and hope I can be of service.I have used things from wool blankets and poncho liners to Gov't issue and Wiggy's.The one thing I have learned is get your self off the ground.It is amazing how much a simple 1/2" inch close cell foam pad can make a difference.I don't care what the rating of the sleeping bag is.If you don't insulate yourself from the ground it will draw the heat from your body.I have seen people get almost hypothermic durring summer while using a 32 degree rated Gov.issue sleeping bag.Sure enough they were not using their ground pads.Four inches of debris or a close cell foam pad or a hammock,what ever!Get off the ground.Why do you think modern man(and I use that term loosely)has beds.The"cave man"slept on multiple furs for insulation.As the original post called it,a sleep system is not just a blanket or bag...