Yeah, Bell's Winter White is one of the best wit-styled brews I've had. I like Victory's Whirlwind and Avery's White Rascal for everyday summer wit drinking (of course, this was back before I brewed. This summer, I plan on having my OWN stock of wit and hefe.)
For some truly mindblowing wit, though, try the Dubbel Wit from De Glazen Toren. Mmmmm. Damn, it's only 10am, and I want one of those right now.