I LOVE my tom tom one.  We bought it a little over a year ago, and it has saved us so many times in the St. Louis area, esp. with all the construction that is going on here.  Sadly, I shop more than ever because I can easily find all the stores in the downtown area that were always out of reach before. 

It is also a lifesaver when on cartrips with my hubby.  It GREATLY cuts down on the inevitable roadtrip fights over stopping for directions.  It is also great for the kids, because I can tell them exactly when we will be there.

The only drawback, is like with every GPS system, you have to...