131 Dragway in Stanton
I-96 Speedway in Odessa if you like dirt, Berlin in Marne if you prefer paved oval racing. The AMA and WoO both have races at Odessa.
Michigan Adventure in Muskegon has a decent water park.
Battle Creek has a zoo where you can feed the giraffes by hand.
The West Michigan Whitecaps play semi-pro baseball, Griffins play hockey in G.R.
Griffins were a Red Wings farm club, they may still have that status. I beleive the Rampage is the arena football team in G.R.
Wild Horses, a Mustang Club has members in that part of the state.
What exactly are you looking for?