Performance wise. When my gangsters go into battle, the fps drops to less than 20. And my laptop can run games like Skyrim at 30fps.

I'd say check the visuals or your graphics card. My laptop stuttered with Sleeping Dogs (less than 30fps at all times) but doesn't have any trouble with Omerta. Still, one case (or two) isn't enough to call it poorly optimized or not.
P.S. Did you try it with the newer patch?

My copy o Omerta is from Steam so it's the latest. I use the lowest settings and battles run like garbage. What is strange is outside of battles, the game runs smooth even with the highest settings.

There are limits to what money can buy or achieve, I'm sure you know that. You must not have tested thoroughly much games here to consider Sacrifice the worst.

edit: copy/paste fix

This ^

Superfrog And Cannon Fodder.

Why?

They are horrible Ports. They should really be played on the OS/Computer they were created on/for, The Amiga.

I kind of enjoyed PC Superfrog.

My vote's for Jack Orlando - though I never knew what Novotnus posted below, that's very interesting! I wonder why on earth did they mess up a better game? :)

Still, I've only played the Director's Cut, which is terrible. On paper it should be something I'd adore as a noir detective point and click adventure is exactly my kind of thing. In reality it's a horrible dead end filled mess of deaths and terrible dialogue and un-fun puzzles - I don't think I've ever been so disappointed in a game. But even without that bias it still safely earns that title of 'worst GOG game' for me, as it's rubbish.

Cannon Fodder!? You whore! You blasphemer! You...you...wiper of other people's bottoms!

As a massive fan of the first 2, I have to say it's Lords of the Realm 3. It was one of the most shocking disappointments of a game.

I'm not sure if non-DC was ever published outside of Poland. It was pretty buggy too, and when fixing those bugs they added a tone of crap and called it Director's Cut. It still had:
- Lots of red herrings (those never bothered me much),
- Deaths,
- Ugly ending cinematic.

It did not have:
- Terrible, lame catacombs part and idiotic obiects you need to pass through it.
- Some minor lame puzzles.
- Dead ends (at least I haven't found any).

It's called butlery, and I'll thank you not to besmirch us all with one duty out of a thousand. Stool displacement is a task rarely ordered by the master, but must be undertaken with the utmost care. We're not savages after all.

My Python reference has been foiled by the inventor of Scrabble. :(

Crusader: No Remorse. Awful, terrible controls.

I have to agree with you here. Although I wouldn't necessarily say LotR3 is one of the worst games on GOG, it was definitely one of the biggest disappointments to me after so completely enjoying the first 2 so much. It seems the same could be said about MOO3 as well...