I like long games, but I don't want to get a game that's too long. I need a good story, one that's fleshed out, but not milked, and I need good gameplay.
10 hours is too short. One example would be Star Wars: Force Unleashed 2. Fun game, quite good gameplay, but then after just over 8 hours of play, I beat the game. There were only, what, 2 boss battles in the whole game? Sure, the story was good, I admit, but when I played for 2 sittings, and then it was "Oh, look, you're finally fighting Vader" I was pissed. And, Vader was way too easy. What happened to challenging bosses? For this game, while the story and gameplay were both good, they were both held back too much because of a lack of content.
Now, another example can be Re:coded. Most can agree, out of the Days-BBS-Coded Trilogy, it was the most fun gameplay-wise. If you ignored the story, that is. And, well, with this being the KH series, you can't ignore the story, and grow a biased view on the game's whole. So, it was dragged down. It wasn't 'till after when you beat the story and you were able to only focus on the extra content that a lot of people were really able to have fun. For this one, it had amazing gameplay and content, but it was held back by a lacking story.
I can't think of a game really were the gameplay dragged down on the story (except maybe Days), but I'm sure there are a lot of them.
The developers really just need to stop being so cinematic with their stories, and just try to make the stories interesting. But, before that, they need to make sure the gameplay is solid, seems fresh the whole time, and has lots of extra content.