Creech is the product of a fully-realized vision where every aspect compliments the others. It was a love letter to 50's Americana and classic Sci-fi/horror movies. It is not the absolute best game ever, but it is one of the best 'packages' assembled, and I love looking at it as much as playing it.
Congo is a great game by the same great team, but it suffers from a completely irrelevant theme. The movie isn't even bad enough to be good, it's just mediocre and forgettable. I'd probably own one for a while, but I don't think it would last long. That volcano shot is pretty awesome, though.
Creature all the way.