I don't think DQ requires grinding. People who say you have to grind slimes are dumb. I guess DQ4 ds was an odd one with me since, I've beaten DQ1, 2, 4, 5, and 8 and the 4's the only one I really had to grind into beat it. Not a particularly big flaw, since it takes all up 10 minutes. But it did leave a bad taste in my mouth. Doesn't matter since DQ4 is probably in my top 3 favorite DQ games as of now.
I tried out The World Ends With You. I liked the idea, but couldn't get into the battle system. I played about 5 hours, took it back to the store and got Final Fantasy III ds. I'd like to try it again though. Since I"m not big on stylus gameplay I'm still skeptical if I should dive in again or not.