Though I have to admit that the endings bummed me out too (you actually can find my rant on this topic in the eponymous thread), out of fairness I should clarify that I DO NOT regret my purchase. I really enjoyed the game for the most part and the writing sucked me right in. Quite honestly, that's why the bleak outcome was such a bummer, I became really invested in the characters and as such was crestfallen when I was railroaded into disaster, especially when I felt it lacked a good explanation. But if this were a bad or even just average game, the endings wouldn't have left me with such a reaction. I would have just shrugged, quipped "well, that's that, I guess" and went my merry way.
TL;DR: Even though I have my gripes about the endings, I still think it's a great game and would recommend it despite its flaws.