I use cryptsy and coinedup, both of which are only for crypto currency - no fiat currency. I like coinedup as I find the withdrawal times are faster, and there are no fees. The only thing I do not like I'd the interface as it is a lot more primitive than cryptsy and other crypto exchanges.
For usd or euro exchanges I think coinbase is better than mt gox in terms of transaction times. I like the interface and platform of coinbase as well.