Probably Nintendo @ E3 2015 and the subsequent abandonment of the Wii U.

i really feel done with Nintendo after this year.  They've consistently proved that they're not changing.

Why? What was the problem?

PS Plus Service

The Witcher 3. I had so much hype that I actually bought it on a pre-release digitally, something I NEVER do. The story was interesting but the characters were childish, the world wasn't special in any way... the game just felt uninspired as a whole. Animations and controls were bad as well, it was tough to do simple things like entering a door. Decent game, but not the greatness I expected. 6/10.

That's my biggest disappointment. The UI is ununderstandable to me, the game is not worth its pricetag.

I guess. The Order 1886. I never thought it would be an instant classic, but I did expect and engrossing story and all. It was pretty good while it lasted, which sadly for me was about 11 hours to platinum.

Of the games I bought.... hmm...... can't really say any of them disappointed me. Guess I just have good taste in video games

I don't know what everyone keeps yapping about, but Fallout 4's engine has clearly been updated from the previous games. Sure, it's the same engine as Skyrim, and while texture work and geometry is marginally better, lighting and natural effects have made great strides. The game is a lot more stable too (especially after the beta patch). Sure, there are some bugs, crashes and glitches, but it's more stable then previous games.
Too be honest, the biggest flaw of Fallout 4 is easily the lack of real diversity in the DCR song list.

Fun fact: Epic Mickey runs on the same engine (albeit Bethesda runs a custom version of it for their games)

The Order 1886 - I enjoyed it but i expected it to be a lot better even after all the negative press it received before release. But i really want a sequel by Naughty Dog, i think they could work wonder's with the ip.

Batman Arkham Knight - Great game but it's nothing compared to it's predecessor's, i truly expected this game to be the top runner for goty.

Project Cars - Had a lot of fun with the multiplayer but it's a very average game and in no way did it live up to the hype.

Devils Third...