I use a GPS MAP 60cs (same as the guys above). It has worked great for me for about 6 years or so now. I bought a 3 CD set of topo maps with it from Mapsource. I just load the maps on for the area I am going to (and quite a bit more) and I'm all set. I also bring a regular map and compass of course.
Now just last week I saw an advertisement for a new GPS that is paired with a SPOT tracker of sorts (same company as SPOT). Anyway, they have a GPS that you can type a message into from the field and send via satellite to people at home via text message, email message and even facebook. Looks pretty cool. The only drawback to this is they want 5 or 6 hundred bucks for it and there is an annual subscription fee. If you're really into the latest and greatest, you might look at this.
Otherwise, I say you can't go wrong with the 60cs (I think now the new model is the 62cs or something like that).
Good luck and if you get the SPOT one, be sure to let us know how it works out.