Well I had a nice long post explaining a lot of reasoning for things, and then my browser crashed, so here's the short version.
Spore - they hyped the shit out of it, corporate came along, told the devs to dumb it down so they could target it at younger kids. Cell and creature phase are fun, tribe and civilization are shitty RTSs, space is a shitty sandbox.
Skyrim - Take Morrowind, dumb it down a shitton so casual gamers can understand it, stick it in a shitty physics engine and an admittedly much improved combat system and ship it. Mods are the only reason this game is playable, though I will admit it can be pretty damn fun then.
Diablo 3 - See Torchlight 2 for what it should've been. Also, just play Torchlight 2 because it's super fun.
Zelda series - I didn't play it back when I was a kid and it was the coolest shit ever, and it's just not fun now. Most of my friends who love it agree that it's mostly nostalgia.
Kingdom Hearts series - Mediocre hack'n'slash that rides on the backs of famous characters from other IPs. 358/2 Days was pretty damn fun, though. I liked how customizable the tile system was.
Civilization: Beyond Earth - I wanted a true Alpha Centauri sequel, but being pessimistic, I pretty much knew it wouldn't be that. I would've settled for Civ 5 in space, but apparently even that was too much to ask. This game was like, Beta Civ 5 in space. Of course, it is a civ game so it'll probably be super kickass after a few expansions, but I definitely regret buying it at $50.