Ilosar
Vault Fossil
But ME2 also had companion DLC.
The first was Zaeed, and came free with ANY copy bought new. It also gave access to the Cerberus Network, which meant 5 DLCs total (Firewalker mission pack, two item DLCs, Zaeed, Normandy Crash Site event), free. The second was Kasumi, and was released post-launch. None of those were important to the plot or special by any means, hell they didn't even have dialog wheels unless you were on their unique mission. The From the Ashes DLC contains a Prothean, a super-important part of the lore, as a squadmate. That's like a DLC selling, I don't know, Morte from PST for 10$. Is he absolutely essential? No. He is really important to the game? Fuck yes.
Additionally, deapite solid evidence to the contrary (his voice files are in the demo ffs) Bioware is trying http://social.bioware.com/forum/1/topic/323/index/9403705 to make us believe that it was completed well after the game went Gold, even if it was (briefly) released to the Xbox Live marketplace yesterday. This is ridiculous.
Apparently Bioware is trying to advertise their game via forcing the UK House of Commons to discuss the existence of aliens and UFOs by having 10,000 British citizens sign an e-petition on the UK's site for petitioning the gov't. I'm not fucking with you all. Would a man with an avatar of Vault Boy grasping a uterus lie to you? Just take a look at this.
http://petition.masseffect.com/
What the hell.