Since nobody ever answered this, and all you 1Ls are in town now (welcome, by the way!)...
Best Restaurants: Arnold's (meat and three)
Best Brunch: Not sure what I would say to this (actually, I would say Richland Country Club, but you can't just go there), but Pancake Pantry is mad popular
Best Sandwich: Maybe Bread & Company for upscale, but Jason's Deli by the law school is actually a pretty good sandwich place
Best Ice Cream: Lately I've been hitting up Sweet CeCe's
Mexican: SATCO is probably the most popular in general (among the Vandy crowd), but Las Palmas has the best happy hour around and there are plenty of other options
Best Bar (Dive): Depends on your tastes, I guess--and I don't go out that much
Best Bar Food: My favorite would be Crow's Nest in Green Hills (especially for NFL Sundays)
Best Wings: Not a Nashville thing obviously, but I love Buffalo Wild Wings (unfortunately the closest one that I know of is out a little ways at Nashville West shopping center)
Best Chinese: It's actually been a while since I have had Chinese...
Best Pizza: Mellow Mushroom and Pie in the Sky (both near the law school) are both worth a try
Best Burgers: A lot of people would probably say Rotier's (which is kind of divey) in the Vandy area; if you want to spend a little more ($9-11 for the burger; fries separate) but have the locavore thing going on, head to Burger Up
Best BBQ: B&C at the Bicentennial Mall Farmer's Market, but any of the places on Broadway are good, too