Suppose it depends on your definition of worst pubs.
To me the worst pubs are those like The Hare and Hounds in Timperley or The Moorings in Worsley, where they look at you as if you're some sort of weirdo if you just want a few pints and not a three course meal to go with it.
I expect the thread to head off in the opposite direction of rough and ready locals in not the greatest parts of town. So I'll go with, The Church/Hulme. The Silver Birch/ Wythenshawe. Ryan's Bar/ Sale. The Park/ Northern Moor.
All pubs I quite like though.