Godlike
Tibarn (Fire Emblem: Radiant Dawn) v Ryu (Breath of Fire IV): My first thought was "Tibarn Slaughters" but...then I remember Ryu4 has Ahryu P'ung in Kaiser form, which is hitting Tibarn's 3x weakness to Wind *AND* his much lower defensive stat. So it depends on several interp calls here (does Tibarn survive Ahryu P'ung? Does Tibarn just flat out kill Ryu? How much of a beating can Kaiser take WITH Tear factored in? What moves of Ryu's get around Tibarn's Evade and Pavise? etc.)
Onion Knight (Final Fantasy III) v Terra Branford (Final Fantasy VI): Onion Knight doesn't OHKO average, let alone a good defense PC like Terra. The flipside, however, is the case, even for a high defense PC like FEOK!
Salade (La Pucelle: Tactics) v Rhapthorn (Dragon Quest VIII): Kneejerk!
Arceus (Pokemon) v Shania (Shadow Hearts: From the New World): Kneejerk again! Thinking Arceus going first and having more resources is a big thing in his favor, though, its possible Shania with Dream Porter and after Santlilobel can get a double turn, act -> double, and hope that kills Arceus in one go.
Heavy
Levin Brenton (Wild ARMs XF) v Adelbert Steiner (Final Fantasy IX): Can't vote.
Warrior (Final Fantasy III) v Knight (Final Fantasy): If Knight goes first? He probably wins a slugfest with better tanking ability and having good enough damage to combat Warrior's. If he goes second? Warrior suddenly LOSES defense from Advance, and if he doesn't use Advance, his damage takes a big hit.
Balthier (Final Fantasy Tactics: War of the Lions) v Queen Zeal (Chrono Trigger): Don't respect Zeal's HP too mcuh, so Balthier should 2HKO or something.
Angeal Hewley (Crisis Core: Final Fantasy VII) v Jenova (Final Fantasy VII): Thinking I allow Thunder of Envy of whatever sin its named after, which makes this fight kind of one sided.
EDIT: Decided that yes, I do allow it, if Angeal is willing to receive double damage from Physical Attacks on the next turn. Reflects the moves flaw of "Can only be used if enemy is behind him" in game. Doesn't change the fight though, near as I can tell.
Middle
Regigigas (Pokemon) v Seraphita (Xenogears): When in doubt, assume Regigigas fails.
Scholar (Final Fantasy III) v Bow (Breath of Fire II): I should actually look into this more, but yeah, thinking Shot goes in before Scholar can do something scary.
Jessica Philomele (Mana Khemia: Alchemists of Al Revis) v Scythe Riebauer (Wild ARMs 4)
Felius Arwin (Wild ARMs XF) v Nergal (Fire Emblem: The Blazing Sword)
Light
Garnet Sunday (Super Robot Taisen: Original Generation) v Blank (Final Fantasy IX): Can't vote.
Bidoof (Pokemon) v Mudkip (Pokemon): I think we had this match once before? In any event, I think it was Mud Slap wins it.
Tink (Disgaea 2: Cursed Memories) v Pikachu (Pokemon): Can't vote.
Cube (Live a Live) v Melody Vilente (Wild ARMs 3): CK needs to rot in the pits of eternal hate.