1) I thought the ending to Alan Wake was okay. It left questions, to be sure, but I figured they would just address them in the sequel. I thought it was a good enough ending for the first game. Of course, the sequel never came around, and while the two DLCs and American Nightmare helped explain a lot of stuff, I still want more.
2) Yeah...the whole first Borderlands game was really lacking some spit and polish in the story department. The certainly improved on it in the DLCs and the following games though.
3 and 4) Never played them.
5) I kind of get this one, but again, I'm okay with "To Be Continued" so long as I know there's another game coming. While I would have liked a bit more closure, I knew that Halo 3 would eventually be out and I could see what happens, so I could wait.
6) Yeah...budget cuts and rushed product at their finest. Honestly, part of me is kind of glad that this game go so butchered, because I don't know if I could have handled having some of my friends turn to the Dark Side and having my other friends kill them, but...yeah, so much potential, gone.
7) I thought the ending to Mass Effect 3 was great. What? Shepard has to take her ship back from a rogue Cerberus operative, and then she has a huge party with all of her friends at her new home as they celebrate the defeat of the Reapers. I'm not in denial. I didn't roll my eyes at the Mass Effect 4 trailer. SHUT UP! IT DIDN'T HAPPEN! LALALALALA I'M NOT LISTENING!!!!
8) Never played it.
I would like to add Half-Life 2 Episode 3 (EDIT: 2, I meant 2) to the list. At first, that ending was great. "Oh man, can't wait for the next game!" My friends and I were all buzzing about it for several months after it came out. It has now been years. The buzz is gone, and the excitement that I felt and wanting to know what would happen has long since faded. It has been replaced with a sense of betrayal, which has also faded to a simple, "I just don't care anymore" attitude. Good job, Valve.