The only reason I'm writing this blog is because of the serious lack of discussion of this awesome game in the official thread.  It seems that users tend to ignore official threads in favor of user blogs, so here I am.  I also think that there might be a bit of hesitation among some to play BioShock 2, so I'll just say this:

If you thought BioShock was a great game, get your ass back to Rapture, pronto.  2K Marin has done a fantastic job in bringing the player back.  Don't get me wrong, critical praise for this game has been strong, but in my opinion the game is still being undersold.  I'm not going to get into a big thing here, it would just waste your time.  Yes,  it's Rapture again, but it's an entirely new experience there.  Honestly, at the point I'm at in the game right now, I have no hesitation saying it's just as good as the first.  Some aspects have actually improved, such as the ability to have a plasmid and weapon equipped at the same time. 

If you weren't impressed with BioShock, or thought it was overhyped, don't bother.  You'll think the same of BioShock 2.  If, however, you're a fan of the first who is on the fence, get off the fence and pick up BioShock 2.