You should go to Niagara On The Lake. It's a nice ride on the Niagara Parkway along the river. It's about a 20 min drive from the Falls. I just got back from there actually. A lot of nice little shops and restaurants, albeit a tad on the pricey side though. A lot of wineries in the area as well, most of which offer tours. Toronto is a good choice too...big city with lots to offer. It's about an hour from the Falls. Traffic can be a parking lot real quick. Stay away from typical rush hour times. Leave here after 8:30 and try to head back by about 3 - 3:30, and you should be ok !! Which hotel you staying at? The Falls has a lot of nice restaurants, but watch out for an extra tax some of them might charge. Only tax you have to pay is HST (13%) and liquor tax which I think is still 10%. Too bad I didn't have a free night we could have gone for a nice little cruise. Enjoy your stay. Keep in mind 50km over the speed limit and they take your car and licence away for a week, and fines can be heavy too.
John