Which ones?

Skyrim: was rather boring because I found the storyline and characters completely uninteresting.

Mass Effect 2: I really don't like what they did to the series with this game.
They removed so much of the gameplay that I enjoyed in the first game, and turned the storyline into a melodramatic and shallow 'Seven Samurai' theme, instead of the exciting sci-fi adventure the series started as.
It was like turning Star Wars or Star Trek into Battlestar Galactica.

Dead Rising : I just remember being constantly angry with the check-point system.

Flatout: Ultimate Carnage: after a while I felt that winning depended more on luck than on skill.

Too Human : a unskippable 30-second cut-scene every time you die...in a game where you die quite often.
People mainly complained about the controls and level design, but none of this bothered me, but a unskippable 30-second cut-scene every time you die drove me mad.

Saint's Row The Third: thought I would like it but the whole game was just too silly for me.

Splinter Cell Blacklist: adapting the game so that it would also play like a shooter made the controls noticeable clumsy and clunky to me, I also did not like that some areas could only be accessed in co-op: 'here's a door, but you can only kick it in if you are in co-op'.

Armored Core 4 For Answer: I think I have to become some sort of scientist to learn how to play this.

Brink: with more creative level-design and weapons this could have been more fun than it was.

Skyrim: was rather boring because I found the storyline and characters completely uninteresting.

Mass Effect 2: *snip*

That reminds me I should play Mass Effect again. Never got very far because of a bug. (couldn't get out of mako no matter what I did.

Dead Rising : I just remember being constantly angry with the check-point system.

Was it the same as in Dead Rising 2?

Too Human : a unskippable 30-second cut-scene every time you die...in a game where you die quite often.
People mainly complained about the controls and level design, but none of this bothered me, but a unskippable 30-second cut-scene every time you die drove me mad.

Wasn't there an achievement for dying a certain amount of times? :P

Splinter Cell Blacklist: adapting the game so that it would also play like a shooter made the controls noticeable clumsy and clunky to me, I also did not like that some areas could only be accessed in co-op: 'here's a door, but you can only kick it in if you are in co-op'.

Dead Space 3 did the same. So frustrating. The 2nd player character has a personality change out of nowhere if you haven't played the co-op parts.

I think one reason why this got so many positive reviews is because Colonial Marines disappointed so many.

Simon the Sorcerer 4 + 5
Just horrible, horrible games. I don't think the new devs had a slightest grasp of why the previous games were popular in the first place.

Driftmoon: completely a meh game if there ever was one. I just can't see what people see about it.

Jack Orlando: One of the worst adventure games I've ever played.

Moebius: I backed it and boy was I disappointed. I should give it a new playthrough to see if I've melloved to it, but I think the only thing I liked about it was the BG art in a couple of scenes.

There's others as well, but these popped in my mind right from the bat.

I bought Stronghold 3 on preorder since I love the older Stronghold games. Stronghold 2 should have been the warning sign really but I have thrown cca. 50€ away. That game is horribly unbalanced, buggy and unfinished. At least I learned one thing. Never preorder anything.

The other one was also Sword of the Stars 2 - basically an unfinished shit of a game that feels like piece of the game were ripped right out of it. That teached me not to buy anything again from Kerberos - at least not at full price.

Grands Ages Rome also was a shot in the dark. I like city building genre and was expecting something like Ceasar games but alas it was not to be.

Warhammer 40.000 Dawn of War II with the need to use Windows Live in order to play which was not specified anywhere when I bought the game.

If I remember correctly DR2 had no auto-saves and check-points, you had to save manually in a safe-room.

Looking at the Dead Rising games in hindsight, what I wanted the most from these games is actually what State of Decay currently offers in its game, its what I wanted those games to be like.

The Dead Space and Splinter Cell series have in my mind always been single-player games, so I don't get the sudden change to co-op. Especially since Dead Space 2 was so successful already.
When you put co-op in a game it usually ends-up being more of an action game, regardless of whether its stealth or horror.

Only game i can say i regret buying is The Settlers 6.

Haven't bought any new games from Ubisoft since then.

https://www.youtube.com/watch?v=cLVxvQ3a2n8

Haven't played Shelter, but I loved the other two, so there's still hope! ;)

Well, games that do not work on linux... Like Towers of Guns.

Since I usually buy games cheap, there's usually not much to regret. That being said:

* A New Beginning
The reviewers tried to warned me, but I like Daedalic, so I thought "how bad can it be?" *sigh* It was just too painful to slog through, but I don't like leaving games unfinished, so I fully resorted to a walkthrough when I got tired of it, halfway through maybe? And the only good thing about the ending was just that, being the end of it. Daedalic, please don't follow through with that cliffhanger...

* Redshirt
A lession on going from gaming heaven to hell in thirty minutes flat. Starts out interesting enough, but after ten minutes you've seen everything there is to see, and twenty minutes later just want it to end. Which of course it doesn't, you have to slog through hours and hours of it before you finally finish, only to get a measly "Congratulations, you win!" screen (or a "I'm sorry, you lost!" screen). Good ridance!

I liked A New Beginning. The writing was pretty decent.
What was it exactly that you disliked?

I have to add Morrowind to the list. Nice looking game at the time but I just couldn't and still can't rap my head round that feckin stupid combat system!

It's just so unengaging. The concept behind the story is interesting, but the story itself lacks impact and urgency; in short, it's boring. The plot twist is poorly set up and explored, the dialogue is bland and preachy, the characters are one dimensional/cliché and the voice acting is wooden and uninspired (I guess the voice actors were bored too). The puzzles are mostly fair, that's actually one of the good things about it, but are sometimes out of context and only there for the sake of having more puzzles (the infirmary on the research station, for instance).

The story had potential, but I think it was poorly executed.