I've played through it a few times. I actually went back and created a new Shepard in ME1 with a different background (Spacer/War Hero/Soldier Class) just to see how it would be different. Plus I was also trying to get a ME1 play-through without a love interest so I could romance Tali guilt-free. I don't know why, but that voice of hers alone is just so damn sexy.
Then once you take in the whole package, she's incredibly intelligent. She knows her way around a shotgun and her body's not to bad either. I get all tingly just thinking about her. Hopefully Bioware will have something to make it up to us in ME3 that we don't get to see her face in ME2. Oh great now I sound like a Tali fanboy.
Anyway, I also got all the DLC, free & paid that has come out so far for both games. I also got most of the achievements on my first play through of ME2, in particular, "No One Left Behind". I just need to get a few of the tactical achievements and the difficulty achievement.