Recommended Released Games : (I'll work on this later, there's an assload of good games for the system)
New Super Mario Bros. - The first real Mario 2d platformer in what, a decade? This has sold like 15 million copies(seriously)and it's pretty solid. It's also really fun to hear your significant other playing it and yelling at how fucking cheap it is, if you're into that sort of thing.
Pokemon Diamond & Pearl - We have a thread about this already, and it's well deserved. Pokemon totally rules, no matter what age you are. Be warned, the people that bought this from the other thread quickly became hooked and put in dozens of hours.
Castlevania : Portrait of Ruin - The latest side scrolling action RPG in the Castlevania line. Some people thought it was too short, but it's an easy 10-15 hours of gameplay + tons more if you want to unlock everything. Some of the best action on the DS.
Mario Kart DS - This may well be my favourite Mario Kart ever, and I'm a big fan of the franchises. Perfect control, plenty of fun challenges, online multiplayer, and not only are the new courses excellent, it brings back a ton of the old courses.
Advance Wars : Days of Ruin - The latest in the Advance Wars franchise. Turn based strategy, so it's not for everyone. This takes the franchise in a bit of a new direction, with a darker and more realistic feel to it, with less emphasis on special abilities.
Final Fantasy III - A 3d remake of Final Fantasy III, which until this release, was never officially available in North America. It still plays like an older RPG, but it's way better than Final Fantasy I or II. If you liked those, you'll love this.
Kirby : Squeek Squad - While not the best Kirby side scroller, it's certainly the best one available right now.
Elite Beat Agents - This is the game you get if you take Ouendan and remake it for North American audiences. Though some people have faults with the song selection, it's still an excellent game.
Kirby : Canvas Curse - One of the earlier and certainly one of the more unique games for the DS. Instead of being a traditional Kirby side scrolling action game, this game features Kirby as a puff bull of sorts. You draw lines with the stylus and he rolls down them. You solve puzzles, fight enemies, and it's just a blast.
Trauma Center : Under the Knife - The original game that started off the series, which is now available on Wii. You're a surgeon and you operate on people with the stylus. Brilliant idea. My only problems were later in the game, when you're operating less on awesome stuff like shards of glass lodged into someone's heart, and more on ANIME PLOT VIRUS ROBOTS. Still, really fun.
Phoenix Wright : Trials and Tribulations - The last game in the Phoenix Wright series. It ties up all the loose ends from the previous games, as well as introducing new enjoyable characters. You could tell that they'd learned a ton about how to tell a story by this one, because it was top notch all the way through. The lawyer games continued with Apollo Justice, which I'll add to this list later.
Hotel Dusk - In a similar vein to Phoenix Wright, this is basically a story that you interact with. However, it's set in a hotel with many mysteries. Your character is an ex-cop, now salesman, looking for his old partner. He shot him during a criminal investigation, and while he's assuming dead, our main guy knows he isn't. Heavy on the text, but quite worth it. Characters were really well done, the style is gorgeous, and the film-noir feel was perfect.
Professor Layton and the Curious Village - This game has been getting tons of hype lately, which I'm sure any of you that were at Katsucon saw. Creative puzzles with free weekly downloads, and a top notch story behind it.
Legend of Zelda : Phantom Hourglass - The direct sequel to Wind Waker. Using a similar style and heavy use of the touch screen, they've put together a really fun Zelda game. This is what I'm playing through right now.
Ninja Gaiden : Dragon Sword - The Ninja Gaiden guys certainly had a challenge ahead of them, to translate that fast paced action to a touch screen interface, but they managed to pull it off.
Contra 4 - Ridiculously tough is how I'm going to put it. If you've played Contra, you know what to expect, but I find this one more difficult than any of the others.
Animal Crossing - Make friends, go and trash your friend's villages online, go fishing, make gardens, that's the kind of game that Animal Crossing is. It's a pretty relaxed game where you just go around and do whatever. Some people get super hooked on it!
Nintendogs - Pretty much the cutest series of games in existance. Though I've linked to my favourite dogs, they have a number of different versions. The different versions allow you to have different dogs, and I think you can trade with your pals and get other dogs as well? I'm not sure. It's pretty much a virtual pet that you raise and have fun with.