I'll vote for Luminous Arc for the Love it or Hate it category. I liked it enough to play all the way through, but... oh man. The story, voice acting, and dialogue was generally atrocious.
It had an awkward experience system, too, and very poorly done menus that made it hard to buy new items for and equip your entire party quickly. Really obnoxious.
I'm optimistic about the sequel. But with FFTA2 and Disgaea coming out, it's hard to include this in the best-of RPG list.
Tony Hawk's American Sk8land... I enjoyed it and was impressed they crammed it all into a DS cart, but it's definitely a fan-of-the-series type game. It didn't do anything different, and had an even lamer 'story' mode.
Am I the only one who really loved TH's Downhill Jam? Now THAT was a nice spin on the series, since it combines the arcade-style controls and insane combos with racing against other skaters. I couldn't put it down.