The bleach games and Jump Ultimate/super stars games are pretty good. Those and mario kart are the only wifi games i really play.
I would say: Jump Ultimate Stars Mario Kart Metroid Tetris If you play random people on the internet Starfox and Advance Wars are very fun, but good luck trying to find random people to play with.
I believe currently the only wi-fi fighting game is Bleach: the blade of fate, but I would strongly reccomend you try Naruto:Ninja Destiny, it's a very good fighting game but there's no wi-fi
Jump Ultimate Superstars and Bleach the Blade of Fate are the solid good wifi fighting games for the DS imo
Personally, I hated Naruto Ninja destiny. The looks may have been pretty, but the general gameplay felt very hollow, and lame. I beat all my opponents by just smashing 2 different buttons continously. The game isn't really that hard. Bleach is the only good fighting game for the DS, unfortunately. Not saying the Bleach games are bad, in fact, I love them, but I'm just saying that there should be games like KOF DS, or Street fighter DS out by now for the DS. Tekken would be fine too. They made a Tekken game for the Gameboy afterall.
I found Ultimate Mortal Kombat 3 DS very enjoyable. Not sure why its overlooked by everyone. I guess because its basically a port but with Puzzle Kombat added.
I kinda wish they would remake Guilty Gear for the ds. Like a Guilty Gear Accent Core for the DS with wifi. I would spend endless amount of time on it if it came out. The Guilty Gear DS game sucked cause they replaced all the movesets and simplified it. Just full of fail.
