about how much time can be put into each

borderlands: zombie island, underdome
mass effect: pinnacle station, whatever other ones there are
l4d: crash course.

Crash course suckeddd

didnt play dlc for borderlands, but the game itself is fun, especially with friends online. mass effect was a tad under 30 hoursi think? cant remember and i deleted my saves. and sorry, never played l4d

W
what's wrong with you,,,.....

I liked Crash Course, but it's buggy and short. But if you liked replaying the other maps etc, you'll replay this one a decent few times, and if going for the achieves, 10-20 replays etc, which imo = 10-20 hours, which is worth 6 or 10 bucks or however many points it was.

I haven't played Borderlands DLC yet, the Zombie Island looks really fun, but sort of short for $10, the underdome seems like there would be a decent bit more bang for your buck though.

Mass Effect has 2 DLC's and if I remember right, both under 2 hours from what I heard.

Don't get Underdome unless you have friends that have it as it's ridiculously hard to solo.