Rock Band
I'm the manager of the Coppin' Feelies, an up and coming video rock band. Last night they won a school competition. Straight to the top baby! Yeeeeaaaaahhh!
As a rule, I don't like rhythm games, since their goals usually involve doing the same thing hundreds of times until you get it "right." But Rock Band has a tour mode that makes things a lot more interesting - you gather fans, earn money, unlock new venues, gain new band perks, and the rewards are new and cooler songs to play. Rock Band also solves the problem of looking like a jackass when you play a rhythm game, because there are three other jackasses right next to you, and you can all revel in your own jackassery. There's a lot of band synergy in it, individual players who fail out can be "saved" with another player's overcharge, and when the whole band gets going it's really a spectacle.
There are options for a solo player too, of course, with a solo tour just omitting the rest of the positions (vocals, drums, lead guitar, and/or bass guitar). Personally I haven't played it too much; just subbing for a player who had to step out, doing easy mode on the drum kit or a guitar or the mic. I'm clearly no good at it, but due to the band mechanic it's still really fun.
Now, there is no shortage of problems with the game, either. One is the high barrier of entry: $170 for the game with its kit (which does not include a second guitar), plus if you want to expand the game's 58-song catalogue, extra songs carry at least a $1 each pricetag. Another is the menu and character system. On the 360 at least, a band's progress and songs they've unlocked are tied to a band leader character - characters are tied to the instrument, which is tied to the controller slot, and to an Xbox gamer profile. If you want to make a band, get your characters right the first time, because changing them will probably involve starting the whole band over.
Also, while the craftsmanship on the instruments is generally good (the guitar's strum shoddiness notwithstanding), the USB hub that ships with it is a real piece of shit. Oh, and all the controllers are wired. C'mon. The 360's Guitar Hero III Les Paul is compatible, thankfully.
So a lot of the extraneous mechanics of the game are flawed. But the core gameplay is really remarkable. If you haven't played it with someone yet, give it a try.
Progress: Straight to the top!