Tips from an Ypsi resident:
Best pizza: Aubree's in Depot Town (about 2 miles from TDIFest, there's another Aubree's closer but the atmosphere is better at the Depot Town location)
Best restaurant (casual): Sidetrack Bar & Grill (about 2 miles from TDIFest)
Best restaurant (Mexican): La Fiesta Mexicana (about 1 mile from TDIFest)
Best restaurant (ethnic): Pita Pita (mediterranean, about 3 miles from TDIFest)
Best breakfast: Gabe's Coney Island or The Bomber Restaurant (both are about 1 mile from TDIFest)
Best beer: The Corner Brewery (about 3 miles from TDIFest)
Best park: Riverside Park (about 1 mile from TDIFest)
Best bike ride: Border to Border trail (along Parker Mill County Park, Gallup Park, and the Ann Arbor Arboretum, starts about 5 miles from TDIFest)
Best golf course (for the money): Green Oaks (about 5 miles from TDIFest)
You can probably find me any day of the week at one of these places.
For those that are looking for a more lively bar scene, Ann Arbor is right down the road with plenty of great bars all within walking distance.