| Animal Crossing is a snorefest, especially if you don't have access to wifi.
Puzzle Quest becomes not enjoyable later on. Lack of items and variety, easy to fuck yourself with the wrong skills.
Tetris is really mindless if you don't have anyone else to play with.
IF you know some other dudes with DS's and you're pretty certain you can find other people to play with, I'd recommend -
Mario Kart DS
Advance Wars DS
Both because they have high replayability even if you can't find people to play with. I'd say Pokemon, but if you're not a fan and you're not comfortable with playing it, you probably shouldn't get it. It can be difficult also without FAQs or wifi.
I've HEARD FF III can get pretty monotonous. Might want to think about picking up some old GBA titles. Maybe Metal Slug or Final Fantasy IV/VI | 