Yes. Yes I have.

I've only bought DLC for Rock Band though. I've spent a lot in that area. I dislike most other forms of DLC though. For example, a few re-skins of maps doesn't seem worth $10 to me. I also hate when games give you much better items than on a disk through DLC like in Dead Space.  And game content that should've been in the game in the first place (that means YOU SCIV).