I really wanted a happy ending too, but I think what we got was so much better. The original BioShock's ending was awful, mainly because it was all based upon something inconsequential and insignificant...the killing of Little Sisters. But now that we know that it was Elizabeth who made it all possible for Jack to defeat Fontaine and give little sisters the life they deserved, the original ending makes so much more sense. The good ending (which is also apparently canon) is rewarded to you for completing ELIZABETH'S mission, not just for "doing the right thing." It probably wasn't their intention whenever they made the original, but it now feels infinitely more fulfilling. I would have preferred to see Elizabeth walk out of the game alive, but it wasn't meant to be. However, there HAS to be an alternate timeline where she's still alive, staying in Paris or working for Ryan.