Garmin GPSmap 60CSx
I've used several units in the eTrex series and the GPSmap 60CSx. I would recommend the Garmin eTrex Vista HCx or the GPSmap 60CSx. Both have an altimeter. Both also have an electronic compass, which in my opinion, is just a waste of batteries, but you can turn the compass off so it doesn't do that.
The Vista is smaller, with a smaller screen, but a good unit and $100 cheaper.
I prefer the GPSmap 60CSx because the receiver is more accurate and handles interference such as tree cover better and there's no delay between when you press the Mark button and when it captures the waypoint. With the Vista you have to hold the joystick in for a second before it knows you want to capture a waypoint. If you're standing still or walking, this isn't a big deal, but if you're passing through in a vehicle, it's annoying. I also have the impression that the GPSmap 60CSx has even better battery life than the Vista, which means you have to carry fewer batteries with you. (Perhaps rechargeable batteries are better these days, but I found 6-9 years ago that they didn't last very long and then were difficult to recharge with a solar recharger. So, it was a lot less hassle and less weight to carry, in the end, to use Duracell or Energizer alkalines. And someone might be able to listen to the radio for a few minutes with them after they won't run your GPS anymore.)
On the Garmin website, the GPSmap 62s also looks interesting, but I have no experience with it. The wireless data sharing might come in handy. I wouldn't recommend the "t" models with the preloaded topographic maps unless you can get them to preload topo maps of your part of the world. I expect that the default set is for the U.S.
I suspect any unit with a touchscreen is going to use up battery power quickly, so I'd stay away from those.
See a response to this on the discussion tab above.