It depends on the game, but generally if I'm playing it heavily, or I feel like supporting the developers because its a great game, I'll buy the DLC. I do buy a lot of DLC. I think the last DLC I bought was the characters and skin packs for Injusitce. before that it was the DLC expansions for Borderlands 2 and Battlefield 3 Premium.

I won't pay for modes or heavy on disk costume DLC like Street Fighter and Dead or Alive have done.

Depends on the game and the dlc. As said before, if I want to support the devs, I'll purchase a few things. I don't do multi player dlc, mainly because I don't do multi player. Extra costumes and characters in fighters, and story based dlc is usually what gets my money.

Currently looking forward to whatever GTA has in the pipe. Hope its not just multi player stuff.

Depends on the game and what it is.
The last dlc I bought was Freddy for MK. Haven't had my own PS3 since then.
Looking forward to what DLC AC Black Flag and WWE 2k14 will have. GTA 5 also.

Next DLC I'm looking forward to is The Last Of Us single player DLC.

I don't buy DLC often, but when I do I make it worthwhile.

The last DLC I bought was a bunch of equipment for Soulcalibur V's character creation mode. I had a ball, too. The first person I made afterwards was the girl from the Addicted to Twerking video, who I named Twerk Girl.

I gave her Xianghua's (or Lexia's, if you want to be a dick about it) weapon style so she'd look like she's twerking all the time!

I don't buy DLC unless it's for a game I really like

The last DLC I bought was The Scorchers for Rage.

I'm looking forward to XCOM: Enemy Within (even though that's more of an expansion pack type thing than just DLC)

I would never buy DLC. It feeds into the whole mindset of 'Let's make half a game, charge full price, then charge more for the rest of the content' cash-over-quality bullshit that's all too commonplace these days. The only DLC i've ever got was free, and even then some of it didn't work! Lookin' at you, Injustice costumes.

I've never actually bought DLC

I've waited for a few complete editions though (Arkham City, Saints Row 3, Mortal Kombat and waiting for Injustice)

Deathstroke for Arkham Origins is looking pretty hard to resist though..I still think I'm going to rent Origins when it comes out and then buy the Complete Edition when it drops.