I'm not a particularly big fan of the MYST series, but from an artistic (and arguable gameplay) point of view, they are wonderful, compelling games. And Cyan is from Texas. Back in the day, Roberta Willams and company made create adventure games at Sierra (now AKA VU). Old School Lucasarts games are still some of the best titles around.
Nevertheless, it's kind of short-sighted and primitive to say "one country makes better games than others." I think French games can have some of the most compelling and tasteful visuals of any game, but that doesn't mean they all play well. And the brits can make wonderful, deep games, but not all the time. The games industry in the US is entering a rather nasty phase in growth, so for the time being it's the demagogues ruining our reputation.
I think it's nicer to be aware what makes a game developed in a different country interesting rather than making a comparison. For example, there is a PC FPS being developed in Russia called "You Are Empty". I find this interesting because slav culture is always worried about leading empty lives, and they really think about what is an empty existence. If the company is able to convey such a sentiment, I think it would be a unique game.
Back in the US, Irrational games is working on Bioshock, a semi-sequal to System Shock 2. From what Ken Levine says about the game, it seems to be very a compelling; a story about what bio-engineering, and genetic manipulation means to us in terms of our humanity. Definitely our view of progress and change is something to talk about.
But to talk in comparison, well then why don't we just start arguing who has a bigger dick? Because in that case the Portugese will win....