a lot of people recommend the etrex yellow as an entry unit for cost considerations, but for just slightly more money, you can buy an etrex Venture, which has a much higher resolution monitor, the same as the Vista and Legend, and it also has a joystick for easy data entry, and a PC cable, which is nice for firmware upgrades, and also as a way to quickly upload waypoints into your machine. It also allow you to store 10 tracks, instead of just 1.
So for just a bit more money, you get quite a bit more etrex.