Hmm, I personally loved Skyrim and still play it from time to time, though that's on PC so I'm able to mod it for an extra enjoyable experience. However, one of the most overrated games that comes to mind for me is Dead Rising and Dead Rising Riptide. The first game looked so amazing. A free roam zombie game that actually looked scary? What else could we ask for!? However, what we actually got was such a bad, broken piece of crap and I was so let down. So much that I seriously considered sending a support ticket to steam, asking for my money back, but luckily I was able to spice it up enough with one particular mod that made it playable. However, the second seemed to get a lot of hype as well and it was the same exact thing, only worse.
Also, here's the mod I mentioned. If you are familiar with Fist of the North Star, you'll get a laugh out of it. And this mod is TOTALLY worth it, and even works when joining multiplayer matches. Listening to people go "What the F***?!" as I fly across the screen and kick a zombie into oblivion is a satisfying thing.
[video=youtube;hoLadZotBuE]https://www.youtube.com/watch?v=hoLadZotBuE[/video]