#1 MC Escher http://www.mcescher.com/
#2 Salvador Dali http://en.wikipedia.org/wiki/Salvador_Dal%C3%AD
#3 Duane Flatmo http://www.duaneflatmo.com/
#4 Agustus Owsley and Bob Thomas http://www.thebear.org/GDLogo.html
#5 Hipgnosis http://en.wikipedia.org/wiki/Hipgnosis
Storm Thorgerson, Aubrey Powell, and later, Peter Christopherson.
#6 Robert Crumb http://www.crumbproducts.com/
#7 Gilbert Shelton http://en.wikipedia.org/wiki/Gilbert_Shelton
#8 Peter Max http://www.petermax.com/
#9 Piet Mondrian http://en.wikipedia.org/wiki/Piet_Mondrian
#10 Leonardo Da Vinci http://en.wikipedia.org/wiki/Leonardo_da_Vinci
#11 Rene Magritte http://en.wikipedia.org/wiki/Ren%C3%A9_Magritte
#12 Andy Warhol http://www.warhol.org/
#13 Mouse/Kelly http://www.dead.net/tags/kelley-mouse-studios-0
#14 Wes Wilson http://www.wes-wilson.com/
#15 Rick Griffin http://en.wikipedia.org/wiki/Rick_Griffin
#16 Joseph Parker http://iasos.com/artists/jparker/
#17 Thomas Cole http://en.wikipedia.org/wiki/The_Voyage_of_Life
#19 Pablo Picasso http://en.wikipedia.org/wiki/Pablo_Picasso
#20 Vincent Van Gogh http://en.wikipedia.org/wiki/Vincent_van_Gogh
#21 Rembrant http://en.wikipedia.org/wiki/Rembrandt
#22 Mati Klarwein http://www.matiklarweinart.com/en/gallery/annunciation-1961.htm
#23 John Pugh http://artofjohnpugh.com/pubimg.asp
#24 Richard Avedon http://en.wikipedia.org/wiki/Richard_Avedon
and…
http://en.wikipedia.org/wiki/Hieronymus_Bosch
http://en.wikipedia.org/wiki/Henri_de_Toulouse-Lautrec
http://en.wikipedia.org/wiki/Pavel_Tchelitchew
and
The unnamed artists at Farmville. Zynga has some REALLY fine art.
#25 gregvanderlaan http://www.zazzle.com/gregvan*
http://www.zazzle.com/fish_yinyang_postcard-239762516340535206