Borderlands. The Vault is talked up, and up, and up. The whole journey is towards it. Hey, you're here! Now fight a tentacle beast and get.........nothing! That's right, you spent the last twenty hours working towards.....NOTHING! They redeemed that somewhat in the sequel, where it's revealed Jack was manipulating events the whole time.
Mass Effect series. I know, discussed to death. Still applies. The whole "organics and synthetics can't coexist, no peace in the universe ever" spiel seemed artificial, arbitrary, and tacked on, especially after I just spent ninety hours over the course of three games showing the various races they COULD in fact cooperate and were in fact BETTER OFF doing so. Nope, sorry, we're throwing that all away in favor of setting organic life back a thousand years because an overgrown Speak-'n-Spell says it has to happen. Thanks for playing, we hope you enjoyed how it was all for nothing! Shepard saying "screw you" and walking away would have been better than that.
Battlestar Galactica. God, the last season and a half of this show drove me batshit. But the ending? "Let's throw everything useful we have into the sun and become cavemen!" That's not escape, nor survival. It's sheer idiocy. And the whole "they are our ancestors -- MIND BLOWN!!" thing the writers were trying for Did. Not. Work. At. All.
Lost. I spent all of season six yelling at my TV: "Stop explaining! For fuck's sake, STOP EXPLAINING!" I liked the first couple seasons, when everything was intrigue. Then in the last season they decided to answer everything, and every answer was so weak, so unimaginative, so disappointing....I liked the whole Jacob vs smoke monster thing, it had a timeless, mythical quality, until it was revealed they were just two schmoes who got shipwrecked there 100 years ago! I liked the wine cork analogy for the island, until it was revealed the island's evil was contained by an actual fucking cork! When the fans invent things leaps and bounds better than what the writers come up with, something is wrong. I'm also perpetually offended by the inclusion of "the Christians are right" heaven/hell bullshit in any story. People who want that crap can go read Left Behind.