Snag cool art to use in non-commercial projects (that means you can't sell them, but you can give them away or make them just for you!) at the Smithsonian! they just put up 40,000 works from their Asian collection. Dive in at the Freer Sackler homepage!
The internet's largest platform for digital art, DeviantArt is a great place to see other artist's works, host your own, or just see what's popular. From scanned pencil drawings to photos to digital art, DeviantArt has a little of everything. It's a great place to be if you're an artist, or just enjoy seeing art made by professionals and regular folks.