An unlikely celebrity cameo is UK chat show host Jonathan Ross, who 'starred' in Halo 3. He supplies the voice of one of the marines who helps Master Chief, although it's very rare that one of his lines comes up -it's a totally random, and rare, occurrence.
Mario is the most accomplished video game character working today, assuming a large amount of roles in video games. In his career, Mario has appeared as a carpenter, a plumber, a doctor, a go-kart racer, a golfer, a tennis pro, a soccer player, a baseball slugger, a snowboarder, an Olympian, a referee, a basketball dribbler, a demolition man and a dancer.
Also, just for the record;
[yt]http://www.youtube.com/watch?v=TK2E5u3BZvw&feature=player_embedded[/yt]
Mario <3's me.