Okay understand this - the more you can afford the more the GPS can do. Memory is critical.
Now for a simple GPS you have great references listed above. I use GARMIN and have for quite a few years. Even the Garmin units I use which are no longer sold are still supported and work just fine.
My suggestion based on what you can spend.
I go for one that allows me to use the Micro cards and they are cheap. That way I can load cards for the many areas I hunt. All units will lay the track of where you have been and can be downloaded onto a computer. Garmin Waypoints program helps you do that. I load topo maps in all my Garmin devices. I hae one for my boat, pick-up, dogs, and me. I have one I give to my partner.
For the money I like the Garmin Rino 530 chx, is a color screen, micor chips can be added, is rechargeable via car or home (battery life is excellent), gives you a 5 Watt radio, Weather forecast for the exact area you are in is instant. Has lots of other features such as back trak, go to, and solunar phases,
I also suggest the Garmin 100K Topo program. You said you wanted to keep track of ridges where you have been and where you would like to go in the future.
Well the Topo program will allow you to download area maps into any Garmin unit you buy.
The beauty of this program is - once back home and uploading where you have been from your Gps TO your computer - You can add Google Earth and see exactly where you have been. Using the Topo and then seeing a real picture of the terrain and where you have walked is to me very useful.
I have an example picture and will upload it soon.....
JW