Aside from the banned gimmicks introduced following the GX series end, Yu-Gi-Oh in it's standard 1v1 PvP format is one of the most successful and popular card game series to exist. It is still played competitively in real tournaments for prizes, and casually played through various online means such as Skype.
That being said, the game is very, very old. Also, despite it's high competitive popularity, walking around in brazen public and seeking out duels will usually make people think you're a tool or nerd.
Do you still play the game, be it casual or serious?