No such list as I'm sure some people rather keep their channel privet.
Its just like the server based channels, but with 'serverwide' in front.
Try ones you can think about. I mean, if you're looking for a monk thing, try monkly or monk. Shaman? try shaman. CastersRealm? try castersrealm. Etc.
I doubt there's a serverwide.market or bazaar, but you never know.
Btw- you create your own serverwide channel, just mistype one: serverwide.bazar. New channel, that dies when last person leaves.