Tapas bar is called La Tasca (
http://www.latasca.co.uk/) but if you want a more authentic experience there's a fantastic place called El Rincon (http://www.sugarvine.com/Manchester/reviews/review_detail.asp?restaurantid=5510&name=El%20Rincon), not the easiest place to find but gorgeous food. There's also more italian based tapas at the lovely Pesto on the corner of Bridge Street and Deansgate.
I you let me know what kind of thing you want to eat then I can guide you better as Iive here.
There's currently an ice rink up at Picadilly Gardens (http://www.onicepiccadilly.com/ice/) there has been a Big Wheel in Exchange Square but think it's just come down.
The Printworks have a good selection of pubs and clubs and places to eat (some love American places such as Old Orleans!).
http://www.theprintworks.com/
Also in the Printworks is a cinema witha fantastic IMAX screen which is well worth a visit.
http://www.odeon.co.uk/fanatic/film_times/s11/ Manchester/
Indian - try Shimla Pinks off Bridge Street.
http://www.shimlapinks.com/
Chinese - there are some great buffets including Yum Yums (http://www.yumyumbuffet.com/) in the Printworks for a budget option or head to Chinatown. There's New Samsi (Whiworth St) if you like japanese esp Sushi.
http://www.samsi.co.uk.
Steak - bit pricey but so worth it - Gaucho Grill off Deansgate.
http://www.gaucho-grill.com/
Italian - San Carlo (http://www.sancarlo.co.uk/) or Piccolino (http://www.individualrestaurants.co.uk/piccolinos.asp).