tripple posting. i just recently played and completed the overlord and shadow broker dlc's for mass effect 2. so far, all of the paid mission dlc has been good, and the free firewalker missions were pretty fun.
but the shadowbroker dlc is amazing if you are a fan of this game. just get it. gameplay, two of the best boss fights across both games. story, a lot of cool shit goes down. i can't really say anything because of spoiling it, but if you know about the shadow broker and whatnot, it's really cool.

that and they made liara really awesome, and updated her character model. the shadow broker dlc is like 800 points though, so a bit higher than the other dlc's, but it's a little over two hours long, and it's a really well made piece of content for people looking for more mass effect 2.