The official one, with new footage and voice over and everything. Surprise, surprise, it's way better. *Spoilers, obviously*
I've talked the original ending to death, and I understand that it has it's proponents, but I still feel that, much like with Mass Effect 3, the ending was bad not because it was sad (which was always a dismissive way to "invalidate" those complaining about both endings), but rather because it was contrary to what the rest of the series had been about.
There are those who say that the ending to How I Met Your Mother was perfect because the mother dies. I don't disagree. That wasn't what got me about the ending. What got me about the ending, specifically, was Robin and Ted getting back together, along with Barney and Robin getting divorced (the very next scene after getting married).
That last episode, or last half episode, or whatever you want to call it, invalidated all of the character development of three of the main characters the entire show. Barney's arc across the whole show was about him giving up his lifestyle as a ladies man because he really had found "the one." Robin, similarly, went from being afraid of commitment to being in multiple long-term relationships, some of which were disastrous. Ted had to learn to give up what he always wanted (Robin), so he could find something even better in the future (Tracy). I mean, we had to endure the scene of ROBIN FLOATING AWAY AS A BALLOON, only so they could GET BACK TOGETHER?
And then, in the last few minutes, Robin and Barney get divorced in the very next scene after their wedding because neither one is actually into the idea of commitment, Barney becomes a ladies man again (although admittedly I did like the part where he falls in love with his newborn daughter), and Robin never gets involved with anyone so she can focus on her career instead, and stay distant from people. The group we've seen established as inseparable and together forever fade apart with a whimper, and Tracy dies so that Ted can regress, literally, to a first episode callback where he runs back to the arms of Robin.
So you know what, no, the problem with the ending of HIMYM was not that it was sad, it was that it sucked. And you know what? This alternate ending is better. It's not perfect, it's even a bit too saccharine, and ignores the actual foreshadowing toward Tracy's death which was all over the show's final season, but it doesn't invalidate everything up to that point, so yeah, it's better. I strongly suspect this ending was almost intended as a jab at those who wanted a "happy ending," but I don't really care, it's way better.
And while we're at it, the (rumored) original ending to Mass Effect 3 was better, as was the Indoctrination Theory. Did people get obnoxious about talking about that game? Yeah. Were they wrong? No, that ending made no sense thematically.