like all others on here, id play the 1st game before the second. i played 2 playthroughs with 2 different characters on the first game. amazing game, and fun all 4 times. I recently bought the second game for 19.99 at bestbuy, and finished my first full playthrough after about a week. i plan to do at least 2 or 3 more playthroughs with it, but i have been busy with AC brotherhood, black ops, and now fable III. Overall, Mass Effect 2 rivals halo 2 and modern warfare (in their time of course) for the best game ive ever played.