Pretty much every single player dlc avaliable except for the upcoming Omega dlc for ME3 coming in November 28.

It may have something to do with the fact that the vast majority of console games (especially the AAA games) are a third person over-the-shoulder perspective, whereas they've played a relatively minor role in PC games for many, many years. Most third person games that come out on the PC nowadays are actually just simple console ports, anyways.

I have around 450 games on my Steam account. Tons of them are major PC titles. A limited number of them are third-person, and of those that actually are third-person, most of them are direct console ports. My roommate on the other hand owns a PS3. I could go through his massive library of PS3 games, and the majority of them will be third-person.
I actually never touched any of the DLC for the entire series. Is it still worth checking out if you've already played through the whole series? Not sure where the storylines of the DLC fit into the overall story of the series.

Consider this: the third person over-the-shoulder perspective was largely popularized by Gears of War, one of the earlier 360 games. The camera managed to convey a strong cinematic feel, projected the player into the role of the main character better than even first person (amusingly enough) and, most importantly, was an integral part of a game that sold half a million games or so.

Now, recall that the PC market has always been dwarfed by the console market and that PC-exclusive games have been the exception rather than the norm since around the time of the release of the PS2. With this in mind, is it so strange that a great deal of shooters these days are third person over-the-shoulder style games, developed with consoles foremost in thought?

Lastly, consider that Gears of War was originally a PC exclusive (I *think*). Make of that what you will.

It's probably best if you do a replay, all things considered. Some of the DLC works fine on its own - there's a token nod to most of it in ME3 - while some of it really plays better if played as a part of the storyline. (Companion DLC and everything Lair of the Shadow Broker and onwards).

Disclaimer: I have not played Pinnacle Station, nor have I played the ME3 DLC aside from "From Ashes", the Extended Edition and some of the multiplayer stuff.

Pardons if my prose meanders a bit. It is well past bed time here, and I really should have gone to bed two and a half hours ago.

I won't be touching any of the multiplayer stuff, personally. I feel like I'm almost ready to play through the full series again, so when I do I'll be sure to pick up as much of the DLC as I can. Hopefully the DLC for the first two games is dirt cheap by this point. I don't expect the DLC for 3 to be very cheap yet, though.

I dont recall seeing any of the dlc for ME2 dropping in price (last I saw they were still the same biopoints since day 1)

Well, that sucks if that's the case. Microsoft is real bad about that too. The last time I had checked on the Fallout 3 DLC's (not the New Vegas ones) they were still like 10 bucks each.