Looking for your input on GPS navigation systems.

OK gang I need your help again. Anne and I will be taking a trip to Iowa over Memorial Day Weekend in May in the Civic we just bought to hang out with one of her best friends. In preparation for that trip one of the things we’re looking at buying is a GPS Navigation system for use in the car. I’ve been seeing all manner of deals on DealNews.com for new and refurbished systems from various manufacturers, but I’m not overly familiar with which features and whatnot we should be looking for. The big three appear to be Garmin, TomTom, and Magellan and prices seem to range from $65 all the way up to almost $400. I’m sure some of you out there in SEB Land have a GPS system or two so I’d love to hear from you on what you think are the absolute must-have features, any favorite models you’ve owned, and what we should plan on spending to get a decent system.

If I’d had my way we’d have bought a 2009 Civic with the GPS Navigation built-in, but this’ll have to do instead so I’m looking to you guys to help me get educated on this stuff.