I'm almost insulted TF2 isn't on that list, although it's technically not DLC, neither is the Snookie hair, so shut up. TF2, for you lucky/unlucky saps who haven't played it, is an awesome game ruined by one terrible feature, hats. There are a number of unique weapons in the game that have their unique abilities and features, but none of those force you to buy them, they can all be acquired in game (with the exception of the Rocket/Sticky Jumper but those are worthless anyway). Hats on the other hand, serve no purpose whatsoever, other than to make your character look good (with the exception of... oh fuck it). These hats go from $5 for crappy old ones to $25+ for new ones, while the weapons that actually, ya know, do shit cost $0.50 or less on average. There are easily 100+ different kinds of hats, I guess that's not as bad as the trains but the sad thing is that people are actually buying them, which makes absolutely no sense to me. Also, there are crates you can find randomly in game, but are worthless unless you open them by buying keys worth $2.50 each. You can get anything from an Equalizer (worth about -$0.30), or you could get an unusual hat, which is exactly the same as a regular hat but with flashy lights that get you headshot (worth slightly more money than currently exists on the planet). I'm amazed this isn't considered gambling, but I have a personal strategy of collecting as many crates as I can, (since they're worthless they are often given out for free by people who won't pay for keys, like me) and then selling them for weapons and stuff I actually want. So I'm basically selling free stuff, and people actually buy them off me! WHAT THE CRAP?!?
Also, Eve Online sold a digital monocle for $70, and I think the game went free to play, thus that is worth INFINITELY more than the game itself. Though TF2 is F2P now so...
I hope no one ninja'd me on this, I wrote this like 2 hours ago but forgot to hit post. This should be the 8th post from my point of view, though I don't hold out that hope.