I personally recommend Garmin GPS receivers (good hardware, software, and customer support) and specifically the receivers with the newer high sensitivity chipsets that provide MUCH better reception under heavy cloud cover, leaf canopies, and inside vehicles.
Whatever you get I'll highly recommend you buy a simple case and a PC-interface cable. Use the cable with EasyGPS - a free program that help you upload/download/manage your waypoints/routes/tracks - available at
http://www.easygps.com. This allows the user to store unused waypoints/routes/tracks on the PC instead of taking up memory on the GPS receiver.
If you just need to capture and use waypoints, routes, and tracks, and don't need pre-loaded maps (or the currently available maps don't meet your needs) then I'd recommend the eTrex H ($95). You'll appreciate the High sensitivity chipset when under forest canopy.
If you want a GPS with on-board maps, then you'll pay a lot more for the GPS and the mapping software costs an extra amount. I'd recommend the eTrex Legend HCx ($215), GPSMAP 60Cx ($320), or the GPSMAP 76Cx ($320). These units have high sensitivity receivers and external memory cards.
If you also want electronic compass and barometer (not really needed by most users), then I'd recommend the eTrex Vista HCx ($250), GPSMAP 60CSx ($360), or the GPSMAP 76CSx ($360).
In general H=high sensitivity receiver, C=color display, S=sensors (electr. compass & barometer), and x=memory card, but the Vista doesn't list the "S" and the 60 & 76 series don't list the "H".
For US street maps add $120. For US 100K topos add$85. For regional 24K topo maps of the national parks add $90 (there is one for western US, one for central US, and one for eastern US).
If you're still learning about GPS technology and how to use them with a paper map, check out the free pdf brochures at
http://www8.garmin.com/aboutGPS/manual.html