I'm a little mixed on it, but I kind of enjoyed Final Fantasy Crystal Chronicles Ring of Fates. The characters are annoying though, and some of the levels can also be irritating, but it has some fun moments. It's not a bad little action RPG.
You can also try Lunar Knights. It's a spiritual sequel to the GBA Boktai games if you're familiar with those. No solar sensor though, still has an internal clock that judges the time of day. I miss the stealth and puzzles of the GBA Boktai games, this one is more a strait action hack n slash and shooter. The only thing i can't stand is the space battles, which you may or may not be able to tolerate. Horrid controls. If you can get past that, you'll find a fun action RPG.
Of course, if you're into more quirky games, you could always try any of the Mario & Luigi games. The third one in particular, Bowser's Inside Story. They're technically turn based, but you can hit certain buttons in combat to do extra damage or avoid damage. Has some clear requirements for reflexes.
Two stylus based games i can recommend are The World Ends With You and Summon Night Twin Age. They're very unique, especially TWEWY. TWEWY is mixed among gamers, but it has gotten consistent praise and i enjoyed its humor. Ignore the emo-ness and realize that it's actually making fun of it.
Lastly, keep an eye out for Lufia DS, remake of the SNES Lufia 2 in action RPG form. Looks good so far, and it's coming to Japan in about a week. Its Japanese name will be Estpolis in case you miss it.
