alright.. so my girl is getting a ds.. and i want to play online with her.. but i'm trying to find a game where i can play with her.. such like diablo or something i can play with her in real-time.. then i came upon animal crossing.. which has this.. but do you do in this game.. and what is there to do online together.. and what happens if i neglect my village and chill in hers all the time or vice-versa.. or something.. wat is there to do together.. and is there another game that would offer more of what im looking for?

well....you can visit her town and her yours.....if you neglect your town....you just get weeds growing and stuff.....you can always swap fruits, which is what you'd want to go online for, so that you have a different variety of fruit trees growing, ALSO, you unlock the 'mall' type store when either you or her (vice versa) buy something from each other's town store at a certain point. You'd have to look it up on gamefaqs.com

Hmmm.....as for games you can play together......you might want to try pokemon? you can battle each other, or dig in the tunnels together....

depends on if you want co-op or battle type.

There aren't that many co-op (if any) games, but battle type there's quite a bit

pkmon is a good game

lost in blue 2 is a great co-op game. of course there is mario kart for battling each other, or the pokemon games are fun for battling and trading (of course).
just go to your local gamestop and buy a few used games. you can take them back within 7 days for your money back if it turns out you don't like them.
that's what I've done 3 times now