Been to Belfast twice in the last month and it's a really great place. Stayed with my friend Jill so can't recommend any amazing hotels but it's definitely worth a visit.
Probably must love horses though... I don't, but they're growing on me :)
Good places to visit at night are Apartment for cocktails, 21 Social (the old Pothouse) although beware 1 particularly self important doorman, and Rain. However, I don't remember too much about Rain due to having waaaay too much to drink before heading there!