well it all depends on what you want, different units have different amounts of "points of interest" this is handy if you want to find banks, resturants, and all that stuff. Also it is better to buy newer gps systems, because many charge to upgrade to newer maps. Also look out for battery life if you do not want to keep it plugged in all the time. There are even gps systems out now that play movies and mp3s, so if you really want an all in one, that would be your best bet. Best way to find the one you want is go to your local electronic store and play with them. Read up on the specs, then make your choice. Try to get one that has a good screen that doesnt smudge when you touch it and the sun doesnt glare on. The interface is probably the biggest thing you want to look at, how easy it is to enter your destinations, and things like that because that can easily make your gps system a great one or one you want to throw out the window. Some gps units can have the route downloaded from a computer or a memory card so that you will not have to enter the information on the touch screen. Read user comments about it on cnet or other websites if you cannot decide. Hope I have helped you a bit.
1994 SSE, 180 t-stat, gucci accented interior, suede headliner, eclipse avx5000 headunit, two 7.8" sunvisor screens, two 7" headrest screens, dvd player / tv tuner, infinity kappa perfect 5.1 components, infinity 12.1 perfect in the trunk, 2 rockford fosgate 350s powers, infinity refrence 7541a, 0 gauge audiobahn high flow wiring, duralast gold battery, sound dampened trunk and doors, xenon-white headlights, 2 15" and 1 20" red neons shine on the back doors, 2 3" and 6 12" blacklights lighting up the whole interior, red leds in the vents, red optx el neon pedals, red streetglow headlight leds, clear corners, pilot seven color angel eyes, blaze seven color underlighting kit, viper 791 xv.