Bit of a brain dump, but....
There's a great turkish restaurant on Deansgate (don't be put off my the neon lights!) called Topkapi Palace.
Southern Eleven is alright if you like your meat.
Australasia - middling sushi, great 'ambience' (a little too much style over substance IMO)
I ate at Entrecôte (on Kingstreet) the other day (50% off food and wine voucher from the food market the other week). A fantastic steak, salad and house red - but not sure i'd pay full whack.
If you're looking to push the boat out, San Carlo's
Value for money, the Banyan Tree is pretty difficult to beat (though mainly Indian food and a bit of a walk).
Panama Hatties on Kings Street does some good Mexican food (on that note, avoid the new Revolution de Cuba - utter 5hite)
There's also a great Indian place on the corner next to Akbars that do some really interesting Pakistan dishes, but I can't for the life of me remember what it's called.