TV's usually have significantly more input lag, which is the main difference you may notice for gaming. Some TV's have methods to try to reduce that, but by and large they are still slower than most monitors. You may also have to fiddle around with overscan settings and other resolution settings to get the image to display properly on the TV.
Other than that, they use essentially the same technology, so it's really up to whichever one fits your budget better and has the size/resolution you want.