I've never been to Beijing club. Dragon i is too pretentious for my liking and you may struggle to get in anyway as guys. Play is decent and large.
The other popular ones seem to be Fly, Levels and there is a new one called C'est La Vie which might be worth checking out. Azure is ok but too crowded.
Drop is a bit more underground, too small and packed for me.
Only other one I have been to is Magnum which is full of young locals.