The Witcher 2 because I can't run it at a playable speed. Too bad I bought it long before the 30-day guarantee. :(

What hardware are you running it on?

I don't think it's really the hardware, I'm running that game with 8gb of corsair ram, a i5 4670k haswell and a palit gtx770 and have those performance problems too. i cant get over 20-30 fps.

What resolution (e.g. 3840x2160?), and do you have übersampling feature enabled in the graphics options?

If you are running in e.g. 1920x1080 with übersampling disabled, I think it should run pretty well in your hardware. I think übersampling is meant mainly for some dual-graphics card (SLI etc.) systems, as it apparently draws every frame several times.

I'm wondering what resolution, with or without antialiasing and what type of AA, anisotropic filtering, etc?

timppu's thoughts above are more or less same as mine. IMHO you should be able to run standard HD resolution without a hitch. Are you using CPU scaling technology such as Speedstep or any dynamic clock modification features/software? I'm not sure if such features impact The Witcher 2 specifically or not, but since I started using a multicore CPU that has dynamic clock scaling (both cool n quiet and Turbo Core), I have found that a fair number of games will malfunction in completely different ways from each other if these features are enabled. Far Cry 1 for example pukes if Cool n Quiet and/or Turbo Core are enabled it will stall on startup for almost a minute or two before running properly. Shut those features off in the BIOS and the game runs fine. Also some multithreaded games will puke or run like a slideshow under multicore and need to have the CPU affinity hard configured to one or two cores to play.

Keep in mind I'm not suggesting that you are having these problems, but rather just throwing a couple of common problems I've experienced with random games out there and found solutions for that a lot of others haven't discovered yet. If it doesn't affect The Witcher, it might come in handy for some other game in the future. AMD has a tool called "AMD Overdrive" that can customize these settings on a per game basis during game launch and I'm sure nVidia probably has something similar as well.

Try lowering the resolution to like 1024x768 and disabling AA and filtering just to see how it runs, then poke around with the settings some more. Make sure of course that you have the latest drivers installed also, and be sure to read the GOG "The Witcher 2" forum for anyone else who might be experiencing the same thing and might have found a solution. Your system does seem like it should handle the game fine though, so something is amiss.

commandos:

I hate this game since i was a kid but I was trying to gift it to someone at one point and made a mistake and bought it for myself. Never installed it and don't plan to.

I've made that mistake too. GOG cancelled the order and gave me a gift key so i could give it to someone else.
Yeah it's ubersampling i guess. But it looks incredibly cool.

I wouldn't go so far to say there have been purchases I regretted, but there have been instances where the memory or nostalgia of a game were bigger than the actual game.

So yeah, it pays to rational about things.

I agree that Tales of Monkey Island was a disappointment, but only because the past games are so dear to me. I just expected more from the series, but it hasn't truly been good after the Curse of Monkey Island.

Disable it. It adds superfical differences if you have maxed everything else. I also recommend you get SweetFX with some HDR and sharpen, really brings out the atmosphere of the game.

Empire Earth. Now matter what compatability mode, virtual xp mode its always something with a mss32.dll which then becomes a lower-level dll problem which then turn into any anonymous problem with no detail just error message.

Easily Phantasmagoria. Just a mediocre, nothing game.

Others worth mentioning:

Space Quest 4 was frustrating, there were some parts that just seemed broken, like trying to get to the top of the hover rink without getting shot. Referring to youtube videos when I got stuck, I could see there was ample time in the video for the player to escape the Sequel Police, but when I played I barely had time to get into the rink before I was being shot at. Parts like that were jut unfair and inconsistent and meant I spent a large amount of time replaying the same part trying different things but with the same result. Humour wasn't memorable either.

B-17 Flying Fortress
Nothing wrong with the game. Just a game with a steep learning curve made even more difficult with a wholly inadequate guide. The pictures in the pdf manual showing the flight instruments are so low res, you cannot make out which pixel is what. And its hard when theres a shitload of dials, buttons and readings. Also wrong information in the manual, took me hours to figure out how to fire the turret. Manual said it was ' when it turned out to be the tilde key. I also couldnt get the autopilot thing to work where I could skip the large periods of uselss flying. All this blindly trying to figure out how to play the game properly robbed me of my will to play it.

What was I thinking!

Most disappointing GOG purchase:

To the Moon - People kept talking about how amazing the story is, how emotional it is, blah blah blah. But I never was able to develop a connection to the characters, so I never cared. I also don't like the script at all, and found that some of the cursing detracted from the dialog (because it seemed out-of-character/random, not because I mind cursing).

That was the only GOG game I played that I regretted spending time on.

Don't play Fez on a full stomach!
space quest 4 was running too fast that's what it was use this!

www.asoftech.com/as/ slow it all the way down! it's not like dosboxes broken speed settings

Dont Starve. I want to like it so much, but its just another collect stuff game without anything happening. The "keep doing stuff to unlock X" model has never appealed to me. I thought DS might be different and I love the atmosphere, but its not enough.