Owltalker is correct, Thai Food from Lamai's Kitchen is absolutely fantastic. It is not fancy by any stretch of the imagination. But you feel like you are literally sitting at home, with your very own Thai grandmother cooking homemade meals for you. I have never had Thai food like Lamai's, many of the dishes are not typical of a Thai menu.
Almost across the street is Emil's, a local Lansing favorite that has been there forever. Traditional Italian food, but everything is made with top quality ingredients, therefore, delish.
Just a couple doors down from Lamai's is Lopez bakery, a great place to pick up homemade tamales and Mexican sweets. It's not really a spot for meals, though.
In East Lansing, try Woody's Oasis for Middle Eastern food. They have a traditional restaurant downtown where the kids are, and another informal place with a deli counter on Trowbridge.
Move further east and you will find my favorite restaurant in the entire area: Akagi in Okemos. The proprieter and his family run this small place in a strip mall and serve up sushi that is incredibly fresh and inexpensive. I lived in Japan for a year, and Akagi far exceeds my US standards (much better than the boring Ukai) with large portions, creative rolls, and again, superfresh fish. Their softshell crabs are bona fide softshells and probably my favorite thing on the menu along with the Alaska roll.
Dusty's and All Seasons are tasty but fancy and expensive, so be aware.
Lansing is boring but the food is great - enjoy!
My all time favorite Thai restaurant is "Thai Food from Lamai's Kitchen." It's on the north side of Michigan Avenue in the same block as the Green Door. Unbeatable Pad Thai and fresh egg rolls. She has a buffet every lunch and dinner; closed in the mid-afternoon. Atmosphere is casual and clientele is ecclectic.
Dusty's in Okemos -- I remember from my time at MSU that it was very good.
Near campus, I loved Harrison Roadhouse (they have ostrich burgers!) and the Mexican at El Azteco. We would go to Clara's for some moderately special occasions, and the food there is pretty good.