The JLA/AVENGERS an original one of a kind airbrush painting after Perez.
The above will also be for sale on Ebay soon, hince the Ebay sample printed across it.
http://www.fortunecity.com/business/bustwo/354/JLAAVENGERSeBaystuff/index.htm
And In the unlikely event your viewing this page and don't know who everyone is, here goes:
First up , the Avengers vrs. the JLA.
STARFOX VRS HAWKMAN, CAPTAIN MARVEL(NOW PHOTON) VRS. GREEN LANTERN, QUICK SILVER VRS. FLASH, VISION VRS. RED TORNADO, IRONMAN/FIRESTORM, SCARLET WITCH/ZATANNA, CAPTAIN AMERICA/BATMAN, THOR/SUPERMAN, BEAST/ELONGATED MAN, SHEHULK/MARTIAN MANHUNTER, HERCULES WONDER WOMAN, HAWKEYE/GREEN ARROW, ANTMAN/the ATOM, WASP/BLACK CANARY and AQUAMAN.
Next up is Wizards Avengers/JLA last man standing.
listing only the heroes not already listed previously.
STARFIRE/FIRE, HERCULES/BIG BARDA, FALCON/HAWKMAN, JUSTICE/RED TORNADO, TRIATHALON/STEEL, NAMOR/AQUAMAN, BLACK WIDOW/BLACK CANARY, BLACK PANTHER/BLUE BEETLE, TIGRA/HUNTRESS, QUASAR/FIRESTORM, GOLIATH/ORION, IRONMAN/GREEN LANTERN, WARBIRD/POWERGIRL, SHAZAM/WONDERMAN, MACHINE MAN/PLASTIC MAN, CRYSTAL/ICE and of course      QUICK SILVER, SCARLET WITCH and ZATANNA all look a little bit different.
The Art of Neal Adams cover does'nt exactly feature a JLA/Avengers X-over but it is probally the first time a Marvel/DC thing was ever published.
The only real significance about the last image is that MOONDRAGON and HELLCAT have never been drawn in this cross- over.