Bitstamp.net is excellent, at least in Europe (usually one day SEPA transfers). It also has modern responsive interface and works very well. Localbitcoins.com i

Bitstamp.net is excellent, at least in Europe (usually one day SEPA transfers). It also has modern responsive interface and works very well. Localbitcoins.com is another good one, it's a P2P exchange where you can also buy/sell bitcoins with cash.