Having bought the PS3 recently, the only games I've bought on launch this gen were Wii and DS games.
Wii:
WiiSports (Bought Launch Wii)
The Legend of Zelda: Twilight Princess (The game was alright, but definitely not what I expected and not my favorite Zelda.)
Super Mario Galaxy (One of the 5 best games I've played this gen.)
Super Mario Galaxy 2 (Just as good as its prequel, but somehow I like the original just a little bit more.)
New Super Mario Bros Wii (Pretty good, but I kind of like the one on DS better.)
Super Smash Bros Brawl (Love the game. WOuld be one of my 5 favorites if more people played it and better online.)
Metroid: Other M (I think the game is fine. Its nowhere near the best Metroid out there, but it didn't 'kill' the series like so many say.)
Muramasa: The Demon Blade (One of the 5 best games I've played this gen hands down. Everyone who owns a Wii should have this game.)
Little King's Story (Was majorly hyped for this game, but it ended up being a mess of ever increasing spikes in difficulty and little information given for missions. And the bosses are frustrating not from difficulty but because they mostly are trial and error.)
DS:
Dragon Quest IV (I am a massive fan of Dragon Quest, but this game made me cry. Not because of the gameplay itself, but the localization team totally ruined the game by adding tons of 'accents' to the characters, changing the context of dialogue and even editing out certain scenes. This is the prime example of a bad localization in gaming, to the point that it ruins the game.)
Dragon Quest V (Much better translation, though not without some bad accents added at random places. But as for its gameplay, its amazing. Upgraded an already good game with new story, a new character to play as and the best mini-game in an RPG ever).
Dragon Quest VI (I'm actually still playing this. But like any Dragon Quest game, so far its awesome.)
Dragon Quest IX (Played it about 70 hours. As big of a fan I am of Dragon Quest, I didn't do all the grotto and monster hunting for the end game. But the main game is still good.)
Kirby Squeak Squad (I enjoyed the game, eventhough some fans didn't. The Angel Power was awesome.)
Kirby Super Star Ultra (Remake of a great game with even more content and better controls. Game is great.)
Pokemon Pearl Version (It was pretty good, but I still liked the previous games better, especially Emerald.)
Pokemon Platinum Version (I tried to play through the game again, but I just got bored. I also didn't see the massive increase in content like I did between Ruby/Sapphire and Emerald.
As for games I'm waiting for to buy first day:
Diablo III (PC)
Star Wars: The Old Republic (PC)
Phantasy Star Online 2 (?)
Batman: Arkham City (PS3)
Assassins Creed Revelations (PS3)
Ninja Gaiden 3 (PS3)
White Knights History (PSP)
Dead or Alive Dimensions (3DS)
Paper Mario 3DS (3DS)
Dragon Quest Monsters: Joker 2 (DS)
Dragon Quest Monsters Battle Road (Wii)
Dragon Quest X (Wii)
Six upcoming games you should look into:
