Depends what you want it for.
For road driving, finding addresses and businesses, I like Garmins (mine's a 260w - $150 at Costco). Make sure you get one that says the street names (i.e: "Turn right on Main St" instead of just "Turn Right").
For hunting, hiking, some offroad driving, boondocking, etc, I like the Garmin eTrex series handhelds.
For racing or hardcore offroad stuff, get a Lowrance Baja series.
For fishing and boating, get a Lowrance.