Planet Puzzle League
There's a good amount of breadth to Planet Puzzle League. I haven't seen it all yet, but so far I'm fairly impressed.
There are a slew of single player modes. One of the new ones, "Garbage Challenge" - in which the player's goal is to destroy as many garbage blocks as possible, as they drop down without end - is kind of a bitch. Most of the other stuff is pretty cool. At first I thought the game's obligatory move-limit Puzzle Mode was pretty easy; but several stages in it's gotten very tough.
One of the neater features is "Daily Play," where the game challenges you to a single round in each of its three main modes, Score Attack, Garbage Attack, and Lift Attack, each with a time limit. The scores for each of these three rounds is saved every day, and your progress is charted over time. Think Wii Sports's fitness chart, but for your block puzzle ability. This is something I have a keen interest in.
There are a bunch of multiplayer options, including single-cart and multi-cart wireless, online friend battles, online world battles, and a bizarre Birthday Battle mode, where you play online against people with the same birthday (saved in your DS, remember?). In a rather ... unorthodox design, Birthday Battle is the only way in which players are ranked online; the other modes don't count. More on this as it develops - currently, all the other players are Japanese, who, as it turns out, are fairly good at this.
Progress: Basic Puzzle 5-3