Just look at any pc multiplayer like Tibia, CS, Halo, Enemy Territory or else and the answer is pretty simple...

Gameplay , but if you want to make a good game , you need decent graphics as well.

Graphics help but without good gameplay, then why play the game?

gameplay

Graphics are getting more important every day, but for me it has always been about gameplay and the interaction that you get from the game.

Gameplay.

Gameplay

Gameplay for sure!

gameplay by far

gameplay