That is awesome artwork, they're all wonderfully done, and I agree the old man has to be one of the best ones, but it's very hard to say which one is actually the best between all of them. But thank you for showing these awesome pictures.
I liked the fourth one with the airplane lady and the funny looking eggs, that shows creativity and beauty. I of course gotta go and check some more of his work out! Thankx for showing us these Stoner!