What are the best classic co-op games?

[Skeeuk]

Xponent said:
The Streets of Rage games were great co op brawlers.

Capcom released some awesome titles such as Final fight, the Punisher, Captain Commando and Cadilacs and Dinosaurs.

capcom was amoungst the best 2 player co op games so your right there.

 i also feel older titles like bubble bobble, contra, nemesis etc are worthy of a shout

also operation wulf was ace back in the day or was it the sequal that was 2 player operation thunderbolt?