I started with a Magellan 315, that and the yellow Etrex are about as basic and simple as you want to get. The few units that are cheaper are actually a little harder to use.
I won a Mag. Sportrak Map. It has many screens for different applications. Once you figured out which screens you use, probably your GoTo, Map/track, Sat. reception and coord's screens, you simply disable the others. You may find some of the maps are too cluttered with useless (to you) info. There is a function in there to hide all the characteristics you don't want.
You may one day realize an application for one of those other screens and at that point you can simply turn it back on.