Which is the best beyblade stadium?

As of 2013, the biggest Hasbro stadium is either a Cosmic Pegasus Beystadium, Darkhelm FX Beystadium, Meteor Fire Beystadium, Volcano Vortex Beystadium, or the Samurai Cyclone Beystadium.

I think these are the biggest, but they are really big. In the future, Hasbro will obviously create bigger and better stadiums so don't worry ;).

Hope this helped!