I am using bitstamp.net, but only trade BTC.
Nice feature is that you can now exchange BTC/USD, BTC/EUR and USD/EUR as well.
Not the bigest exchange, but IMO very professional.
You can also lower your fee per trade if you do a lot of trades, but I guess that is present in some form everywhere.
Hope this helps
That's the global bitcoin trade into fiat pair. I think if that was including into the biggest, below the bitfinex and some other. Fiat pair is not a feature if you can try for a look at their margin or statistic and it that was offering the easy understand for you to read the margin and statistic, You might think if it was offering the most comfortable platform for you.