Games are boring.

I don't think it's the gameplay.

Are there any games with an intelligent concept or plot, or in the least ones that can be taken seriously and don't either have slapstick humor (Planescape) or a corny basis (Xenogears)?

>>11
Hmm, I think you would like System Shock 2 although it doesn't have much of story, but very good atmosphere. Ofcourse it has some humour, but there's not lot of it. Fallouts are both(especially second) very non-serious, but you might like them too. You should also try interesting surrealistic adventure game called Sanitarium. Also if you like Lovecraft you should try that new Call of Cthulhu game. It's not perfect and turns from adventure to shooter oriented towards end, but it's still pretty nice.