Depends on the exchange rate. Most of the times I pick cryptsy because it is easy to do everything there haha, and they have a lot of altcoins
Exchange rate did not diff that much when I checked the sites yesterday.
Maybe you could earn a living by arbitrage on these sites?
Cryptsy, awesome support staff and they trade almost everything there. Been trading there since it opened back in May.
What about fees? Do you have to be a member to view them?