City are at home at dinnertime so there should be loads of people around from about 9am in the pubs/bars from both City and Sunderland (who always bring about 2800).
There are loads of decent pubs in town. I prefer them to most of the bars and certainly more than all the Weatherspoons.
If you get into town at a decent time you'll have time to go to loads of places.
Head down Princess Street past where the student/indie club Fifth Ave is and under the bridge on the right is Charles Street where there is Joshua Brooks
www.joshuabrooks.co.uk/main/ on the corner (excellent night spot for anyone staying in town afterwards) and next door to that is the Lass O'Gowrie which has just won a 'Best Pub in Britain' award. Head down Charles Street and you go towards Oxford Road where there are places like The Thirsty Scholar and further up Temple Bar.
All great drinking places.
Northern Quarter
northernquartermanchester.com/ is spot on. There are literally dozens of pubs and bars. Head for Thomas Street (opposite Shude Hill Met Station) and there are loads together, and just roam around and you'll stumble upon loads of places to drink (and eat - Troff do a great full English breakfast!).
Shambles Square (the place someone else mentioned as being opposite Selfirdges) is good. Sinclair's, the Wellington and the Mitre have fairly big outside drinking area, and the Crown & Anchor is just next door.
Close to St Peter's Square and opposite the back of the townhall is a Weatherspoons called the Waterhouse. Next door to that (at the back) is the City Arms and the Vine Inn (close by is Tiger Lounge). They are decent boozers.
Then you've got the more obvious (which will be more rammed, probably more expensive, with much worse choice of beers and arguably clientel), more cheesy, more commercial bar areas like Deansgate Locks on Whitworth Steet West and Deansgate and The Pritnworks.
Plus obviosuly the Quays area and pubs around Old Trafford itself.
I'll be out all day as i'm going to watch City at dinnertime so hope to see some of you around town!