The Web Museum is where I got these pictures.

One of my favorite pictures is by Raphael...the School of Athens:

And some more of my very favorites :)

Seurat	Velazquez	Van Gogh	Botticelli
Botticelli	Renoir	Degas	Cassat
Degas	Monet	Renoir	Unknown babylonian
Cassat	Unknown Persian	Renoir	Unknown Egyptian
Monet	Seurat