I have all the DLC for Mass Effect 2 because it's easily one of the best games I've ever played, I was eager to get more. Hell, don't even get me started on how hyped I am for Mass Effect 3. I have 3 files ready for transfer already. With the exception of the 'Genesis' DLC which is unnecessary for me as I own the original Mass Effect, I've played and finished everything for both games.
I also have all the current DLC for R.U.S.E. I think the game's great so I've got all the extra stuff so far. The Chimera pack with the extra missions, the Manhatten Project, and the new one where I can play as the Japanese. I don't understand why nobody plays this game. A strategy game that requires genuine strategic thinking. Get it on the PS3 so it's Move enabled and it's even better because it essentially gives you traditional mouse controls. I bought the DLC 'cause it was great value. Adds a tonne of new stuff.
I don't tend to buy DLC very often though. Unless it's for a truly great game then I rarely deem it worth the money. If there's one thing I detest it's having to pay for DLC that's already on the disk, to me that's basically theft. When I paid for the disk I paid for everything on it. I OWN that DLC already. You have no legal right to charge me for it again 'cause it's mine already. You're making me pay for my own property. FUCK YOU.
I will tip my hat to developers that release a 'Game of the Year' edition with all the DLC included, like Dragon Age Origins, Elder Scrolls IV, etc. On the one hand I love that the DLC is on a seperate disk, because when my nephew bought the Oblivion GOTY, I borrowed the disk from him. On the other hand, I do wish it'd play from disk at times 'cause I only have a 20GB hard drive for my 360 and stuff like Dragon Age Origins can take up over 4GB easily.