Saints Row 2 is a really nice follow-up, even in the wake of GTAIV. It's way more polished than the original, it offers a metric ****ton of customization and fun side missions, and the driving, while not as grounded or amazing as GTA's, is still nice once you switch the controls to acceleration with the shoulder buttons (it's 2008; I refuse to drive with face buttons). The style bonuses are really cool, too, since you get respect boosts from things like head shots or driving in the wrong lane.
The most enjoyable aspect of the game, though, by far? THROWING PEOPLE! Or just holding on to them and executing them. That's great, too.
Also, about the voice acting: