Ocarina of Time. I've played it on the N64 at the time and also on the 3DS. It's a fantastic game, but I don't honestly see and never have seen the "OMG GAME OF THE MILLENIUM!" hype around it.
Pokémon games as of late. I haven't played the latest iteration (X/Y), but the few generations before the games have been very bland. I know
Black-Ice will eat my head, but honestly the series has gone stale.
CoD: Ghosts. One of the largest disappointments for the PS4. Expected something along the lines of MW2, got a few hours of nice FPS, but otherwise.. shit.
Thief reboot. Save your pennies and buy the originals off of GoG.com or other sites. The sad part of trying to reboot a franchise and you end up making it something closer to a brawler..
I could go on, but the amount of content versus costs is a big factor for me. Also some games go into the category of "Lets name the game "X" and all people will relate it with the previous successful release "Y" and buy it!". But I digress. I could take a picture of my post-NES generation game libraries and cross out about 50-75% of the games as bad/worse than based on reviews and/or media coverage. Not all games are gems and not all gems are games I like.