Get your tickets and join the crowds at a game at Sahlen Field. If there's nothing scheduled while you're in town, you might like to check if they give a guided tour of the facilities.
Sahlen Field has an admission fee and is a well-known attraction in Downtown Buffalo. There are loads of other interesting sights nearby, so why not stick around a bit longer? Buffalo Zoo, Buffalo Museum of Science and Buffalo and Erie County Botanical Gardens are also favorites among many travelers.