PaintShop Pro works pretty good, in many cases I use it instead of PhotoShop. I can put Ted Kennedy's head on an orangutan's neck a lot faster with PaintShop.
http://photobucket.com/albums/v244/tsiya/
I concur. PSP is the way to go. Gimp is ok, it's free, but it IS limited. Spend a few bucks and get PSP.
Ha! Putting Uncle Teddy's head on anything is a HUGE task (one should wear a truss).