Some good options for creatures I've seen in the cube I play in have been the "magi of" (magus of the moat, magus of the moon, the arena, the disk, future, the library, and the vineyard for my playgroup), mother of runes, some of the specters (hypnotic and nightveil mostly), boggart ram-gang, zozu the punisher, eidolon of the great revel, hero of oxid ridge, orcish lumberjack, etched champion, and lodestone golem have all been good for limiting the ability of control decks or making non-control decks more viable. We play 1v1's, so maybe their playability will be a little worse for you, but those seem decent enough. Good equipment also really makes the creatures in our cube good. You probably aren't going to play with every sword, batterskull and jitte, but even things like runechanter's pike, lashwrithe, bonesplitter, whispersilk cloak, grafted wargear, fireshrieker, loxodon warhammer and all the other tier 2 ones can really beef up almost any deck that wins by turning guys sideways.
If you want your cube to be more diverse, maybe playing with some strange off-color effects wouldn't be that bad either. Adding restock and/or harmonize to green, mana tithe and sunlance to white, dark ritual to black is awesome, and really helps out a lot of archetypes.