My latest acquisitions include:
Jump! Ultimate Stars
Puzzle Quest
Phoenix Wright: Ace Attorney
Phoenix Wright: Ace Attorney - Justice for All
I just finished clearing the last of the missions (including SP (secret)) missions in the adventure mode, so I'm working on doing some fights so I can "level up" the characters I have to get all of the different panels for each character. Right now I've got a few teams put together. My main force had been Nami 6-koma (One Piece), Sakura 6-koma (Naruto) and Luffy 5-koma (One Piece), but I've recently switched out Luffy for Don-Patch 5-koma (Bobobo-bo Bo-bobo) so I'd have a laugher-element character. (The other "elements" being power and knowledge.) It makes a good combination. Nami is great for damage and control (especially crowd control), Sakura is a powerful ring out character (her mid-air weak attack drives an enemy through the platform they're on, at a diagonal, and her special does good damage and blasts enemies forward), and Don-Patch is much like Luffy 5-koma was—a good, fast comboing character. The deck has Naruto 2-koma as it's support (supports are 2-3 koma panels that, when touched, cause the character to come out, do one move, and leave), which does Harem no Jutsu to temporarily stun the opponent, but I'm planning on switching it out for something better. It does still have one flaw I noticed though . . . while Sakura is my Power character, her special is actually Laughter based, meaning I don't have a power based special in that deck. That may be what I replace Naruto 2-koma with.
I've got another deck with Kenshin 6-koma (Rurouni Kenshin) and Gintoki 6-koma (Gintama), which has three supports for when I had a mission with an objective to use a support to KO the enemy. Gintoki 6-koma is made excellent by adding a help (1-koma) character next to him that grants the triple jump ability. His special drives a motor scooter straight forward, driving your enemies in front of it, then exploding at the end. You can easily drive your opponent off the stage with it, and the triple jump ability ensures your safe return.
I tried a One Piece exclusive deck with Luffy 8-koma and Sanji 6-koma, but Luffy 8-koma's moves don't combo into each other well, and he actually knocks the enemy down
too much, interrupting your attacks. (He does have one hell of a long life bar though.) I also tried Naruto 8-koma, who was far too slow to be effective. Just when I thought that was going to be the nature of the supposedly-powerful 8-koma creatures I came across Sasuke 8-koma; fast, and very effective. I haven't built a deck around him yet though.
I was quite surprised. Normally you expect the lesser-important female characters in an anime fighting game to get snubbed on the power level, but Sakura and Nami are among the more powerful characters I've used (although Nami's 4- and 5-koma versions aren't much good at all).
I haven't tried the game online yet, although I did go online long enough to get my friend code created.
Puzzle Quest I've reviewed based on the demo before, but having played the actual game for a while, and having had a chance to taste some of the more powerful enemies, and the system of creating items from runes you can collect, I'm glad I did buy the game, it's reinforced my interest in it.
And Phoenix Wright. Now that I've played it, I can't imagine I didn't get this game sooner. I've since beaten the first one, and just picked up the second one today ($20 used, which I thought was a pretty good deal). That game is absolutely hilarious, and very fun, and does make you think too. When the third game comes out, you can bet I'll be picking that up as well.
My hunt for the G-Pak has failed by the by. The local EB Games isn't even aware of the existence of cases that hold more than 9 games. Future Shop (naturally) didn't have anything, and while I knew it would be futile, I even checked the local Walmart and Zellers since I had to go to the former anyway, and the latter is in the same mall as EB. So as of right now, my collection continues to be somewhat cramped in a 9-game case that I could fully fill two of.

I think I might browse eBay later. I'm not inclined to buy one off EB Games when they charge rather high shipping, and pick a random colour; I really don't want a hot pink DS case.
Anyway, Puzzle Quest is win, the other three games are all über-win, and that's what it all sums up to.