I played the first half of FarCry. I think the gameplay is pretty good, but HL2 is much, much better, mostly because FarCry has a fuckin' lame story...
However, FarCry had been a revolution in gaming because of it's graphics and physics and it has a great impact on later FPS games. I doubt that games like Call of Duty 2 would look like it look without FarCry and HL2.
I read a lot about Crysis, they hired a profesional scriptwriter(they don't want to give away his name, so it' probably some shithead) and they expect the plot to be "breathtaking", the graphic once again will be a 100% revolution. But what I think will be the best, is AI, of course if the developers say the truth. The enemies won't be guided just by algorithms. They will be independent AI systems with sensors that react on situations. This means that there will be no scripted oponnents that always do the same thing, every "load" will give us a new reaction. This should apply also to bosses, like giant alien spiders or other developer's stupid ideas.
Unfortunately I hardly doubt this will run on my machine