Lots depends on your interests Eve. Maybe try one of the guided walks
http://www.newmanchesterwalks.com/
Which tick the box of being on transport routes, but different.
The museums and galleries in Manchester are knock-out, and free entry, so if you haven't explored in a while try the one on Oxford Road, the City Art Gallery, the People's History Museum, the Science & Industry Museum
If you get to Salford Crescent Station, Peel Park with its museum is nearby on the Salford University campus
Ordsall Hall is fascinating if you like old buildings but not the easiest to get to - and sadly in a fairly run-down area