Flew up to Buffalo for a couple nights last fall. It's definitely a great city. There's a lot of architecture, particularly from the late nineteenth and early twentieth century when the city was an economic powerhouse. Wright, Richardson, and Olmsted projects can still be found throughout the city.
It's a fascinating town, but has been set back by the migration of industry south and overseas. Still, plan on eating well (wings!)
Don't forget your passport, since Niagara Falls is less than 40 minutes away. Going to the Canadian side of the Falls gives you the best views, but you need your passport nowadays.