I'm a big fan of the Numyth Tohil lighter from Goinggear.com. Fantastic lighter! It's a little bigger than your common peanut lighter but very well made. It's got a silicon O-ring to keep the fluid from evaporating on you (I filled my first one about a year and a half ago and it's still running on that first fill). The Tohil is also very very well made. I eventually bought four of them, all in orange. Hard to lose if you drop it. The bottom is flat so you can stand it up like a candle (note: they don't advise is as it can get pretty hot but if you need to do it to get a fire going it's an option). Overall a very well made bit of kit, and you can replace all the guts as you would a zippo.

I have peanut lighters scattered throughout my kits; a couple times a year I put a few more drops of fuel in them and after two or three years they need the O-rings replaced. Generally each kit has a Bic (with the button secured by a cable tie) and a peanut lighter.

The Tohil that Phaedrus mentions feels a LOT more well-made and seals up super-tight. I only have one but I like it a lot.

My favorite lighter is a Mini Bic. I personally have not had one fail. I have some Mini Bics that are 4 years old and still are full of fuel. They work on the top of mountains in Tahoe. I think they are over-engineered, but their low price and throw away status causes people not to favorite them.

My second favorite is my County Comm peanut. It does not leak fuel at all after I upgraded the O-ring and really hammer down on the tightening. The County Comm peanut has an upgraded shell over the cheap Chinese peanuts you can get from DX.com, but the guts appear to be the same. The shell upgrade justifies the added cost because the cheap Chinese peanut feels like it is liable to break if I drop it.

I do not own the Tohil linked above and frankly don't feel a need to own it.

I also tote a County Comm peanut and I like it a lot.To date I have just refueled it periodically. What is the nature of the upgrade you perform to keep it from leaking?

The peanut lighters are great, but I keep losing mine.

I purchased a peanut lighter from ebay and was less than satisfied. Initially, it worked great. It stayed filled for quite a long time. Unfortunately, the elastic gasket started failing and then it was pretty much useless.

I put this O-ring on my County Comm Split Pea Lighter:
http://www.oringsusa.com/catalog/product...it26noks59osvg3

They're only 20 cents each plus shipping. It's noticeably thicker and sticks out a bit. So, if you want your peanut lighter to look sleek and pretty, this O-ring is not for you. However, if you want the fuel to be in there for a year or more (assuming no use), then try this. Remember to tighten as hard as you can.

EDIT:

Note that the O-ring linked above fits my County Comm peanut lighter just fine. However, when I re-order, I will be buying this O-ring for a slightly tighter fit:
http://www.oringsusa.com/catalog/product...it26noks59osvg3

I also like Mini Bics and generally have one with me when out on trips. They do work just fine. The Tohil is a luxury, something you don't really "need" but it's like a Rolex- much higher quality than you need. To me that's just fun to own and use. In a world full of stuff cheaped-down to meet a price point it's pleasurable to use something that's solid and well made sometimes.

And the tabasco sauce bottles that come in MRE packs are excellent spare fuel carriers.
A Zippo is really an EDC item, use it, refuel it. Bic lighters etc are great for survival kits, however they do have a couple of weaknesses:
1) Not substained flame.
2) Can be problematic below freezing.

You can shove a zippo under a pile of damp tinder and be reasonably certain of starting a fire.

I found a Bic in a frost covered field one morning, so a Bic under that pile of damp tinder would probably work too. Morning of Jan 5th