I resisted for so long playing the games, the dialogue wheel bothered me- and in the case of Dragon Age 2, I grin and bear the VA but Jennifer Hale's awesome and so is the Mass Effect series. I've played the first two games dozens of times, cross platforms with PC/XBOX 360 and the third game, I found out what happens and I progress what seems a minute further into Priority: Earth a month in my main playthrough, hesitating to resist having to use my imagination to fill in what even the EC left cut and it's silly but once it's played DLC not withstanding, the game's all used up. I can replay but that first personal completed playthrough is priceless.
My favourite DLC packs are Arrival and Bring Down the Sky. I have a lot of Shepards but my main playthrough is Female Shepard, Paragon/Adept/Sole Survivor/Earthborn. The second game, first time round was a pain as an Adept (the class got a little messed with in the second game) but I adjusted. I classify my only Vanguard playthrough as biotics on stimulants- it's a lot of fun but high risk.
Mass Effect 2's Story DLC: Included with brand new copy of game (Zaeed: The Price of Revenge, Firewalker and Crash Site), Kasumi: Stealing Memory, Overlord, Lair of the Shadowbroker and Arrival. You'll want to play the last two after the main mission in two is complete as they are much more fulfilling that way.
Be careful with the third game's multiplayer- there's a PC bug (not sure if it ever got patched) where a multiplier is scaled down to zero- making the game impossible to complete when it's played. I've never touched it for that reason- that and L4D2 is enough of a pain with my ping without adding a different game.
I'm practically a biotic specialist at this point so if anyone wants to play a biotic I'm more than willing to give pointers and advice. But, yes I love the Mass Effect series although KotOR I and II will always have the special place in my heart.