I used to live in Buffalo, NY so Niagara Falls was very close by. It is very gorgeous there. I actually like seeing it in the winter more than the summer... You have large icicles that form on the edge of the falls that just perfectly frame it. But winter in Buffalo is not really fun to drive in, esp. if there is a big snow storm (can you say lake-effect snow!) There are also many other attractions around the area... Niagara (the actual city) has a botanical gardens which is beautiful in the spring / summer, there is a marina and a zoo in Buffalo, and Casino Niagara in Canada. Buffalo also has several sports teams: the Buffalo Bills (football) and the Sabers (hockey), and minor-league baseball team (the Bison). University of Buffalo also has there own sports teams, and they also host plays, musicals, and other performance arts to watch. And don't forget the food! Buffalo Wings originated at the Anchor Bar in Buffalo. And beef-on-weck is another dish known in the area.
Around the beginning of July it seems like there is a huge party atmosphere in the area... Canada Day (that country's "birthday") is July 1st and the US has Independence Day on the 4th. There is usually a bunch of vendors, food booths, etc. around the area celebrating the 2 national holidays. And of course fireworks in the evening.
And if you still can't find enough to do in the area, there is Toronto (Canada's largest city) only a couple of hours north, which has many of the big-city attractions like Medieval Times theme-restaurant, the Canadian National Exhibition, orchestras, etc.