If you don't need the "fancy" features of the GPS (bluetooth, etc), the tomtom One is $199 right now. They just came out with a new model (3rd edition, replacing the old model). For the price, you can't beat it.
The big difference among the models i saw (between Garmin and TomTom) is the garmin says "turn right on main street" whereas the TomTom says "turn right at 300 yds". Granted, i didn't play with the advanced functions like phone integration, etc, i was more focused on the actual GPS functionality.
Their GPS chips are fast and fairly accurate. The biggest gripe i've had is the battery life...it'll last about 3 hours if not plugged in to the DC in the car. So i just leave mine plugged in all the time. The newer models have better batteries.
For those who don't need the fancy stuff, but want a big screen, check out the Tomtom One XL. It's the same thing with a 4.3" screen (instead of 3.5"). $349, not quite the same bargain though...