You will get loads of candids in Market Street, buskers as well. Urbis and the big wheel can make for some nice shots. The good thing about Manchester centre is that it's quite small and everywhere is well within walking distance. Just wander about the back streets and you'll find loads of old architecture sitting alongside new glass buildings. Try Spinningfields off Deansgate for ultra modern glass buildings, you'll also see Beetham Tower just on Deansgate which would be great with a wide angle lens and the Cathedral which is a stones throw from Urbis.
