After quite a few years of using "outdoor" GPS's of various capabilities, I've boiled down my own needs to (beyond the basics most have):

-Mapping - the reality is that although the primary function of the GPS is to produce the current location's coordinates ... eventually I had the desire to actually view the current location relative to features around me.

-Electronic Compass - though this is certainly not needed, I find it helps that my current GPS (Garmin GPSMAP 60CSx) can point to the destination waypoint while I'm standing still.

-External Memory Card - IF you get a GPS with mapping, do make sure your unit has an external memory card capability.

-Fast-Lock GPS Chipset - Most of the newer GPS units have a GPS chipset that allows the unit to lock in amazingly fast - even under fairly substantial vegitation cover. These days the old style GPS chips are almost unacceptable, especially since I don't leave my unit on as I hike. I hike, stop, turn the unit on to get a waypoint, and then turn it off to save the batteries.

-Battery Type - My own preference is for all my electronics (GPS, headlamp, weather radio) to use the same battery type - so I don't have to carry a bunch of different kinds. Lately that seems to be AAA batteries, but unfortunately my current unit takes AA batteries. On the other hand, AA batteries (I assume) tend to last longer than AAA batteries.

As for ease of use, I find all of the Garmin units I've had to be easy to use. Even my young daughter - without any instruction - had been able to figure out how to set up the GPSMAP 60CSx to navigate.

If all you want is to get GPS coordinates and capture and use waypoints, then the Garmin eTrex H should suit you well. Garmin is about to come out with a new eTrex, but I'd imagine they would be more expensive than the current version. Actually my Garmin Geko is a great tiny unit, but alas it doesn't have the more modern chip set (and it out of production - but sometimes findable on-line).