Also, one thing I enjoyed about the Paper Mario series is that across the games, Bowser had been getting progressively less and less evil. He goes from big bad, to goofball, to guy who reluctantly teams up with Mario, to guy who wants to know when the next Mario Kart tournament is and doesn't even know why he's fighting Mario when unpossesed, to guy who just wants the best for his son and admits he's nothing without Mario. Doesn't even bother fighting him in ToK.
Character progression at its finist.
Well, except for Sticker Star, but then again, everyone regressed in that game.