Tough decision. Considering Blooey's a Blooper, he'd probably have some cool ink-like power. I wouldn't pick Jerry (too much like Bobber), though. Torque has that moon-shaped spike coming from his shell, which could be cool to use, and screamy is all mysterious. I wouldn't pick Hayzee 'cause he's (she's?) too plain.
Screamy's winning. Hayzzee would have to be my second (who is also in second place) and Blooey scores third, because those three are unlike all of Mario's partners. Jerry and Torque seemed kinda.....I dunno, boring I guess.