Hey Riker,
Having both a Panny plasma at home and a huge 128" projector screen (Panny PT-4000) at my in-laws place I would take the clarity of a plasma anyday. The projector is good, but the detail in a direct view set can't be beat. That being said, a huge screen does have an impact when watching movies.
If you go the projector route, mounting becomes very important - especially in the basement. The ceiling you mount to will move when people walk directly over head, I suggest going with wall mounting to avoid the bouncing image issues.
My 2 cents for the day.
