I like Koromori, it looks like something from Dragon Warrior Monsters (one of my favorite games). Lots of the new monsters look pretty cool, but, as I said before, defiantly don't look like pokemon. Victini is pretty kick ass.
But then again some of them just look ridiculous, and/ or are based off animals that have already been done (better) in previous games. A couple examples would be Yanappu, Emonga, Desukan, Denchura, Tabunne and a few others.
And although Tamagetake and Baffuron will never replace Voltorb and Tauros, respectively, they still look pretty badass.