Top Exchanges that support Ether

Each of the following Exchanges appear in the Top 10 interms of their volume of transactions:

• Poloniex - USA
• Kraken - USA
• Gatecoin (currently down) - Hong Kong
• Gemini - NYC, USA
• Exmo - Spain
• Yunbi - China
• Bittrex - USA
• Bitfinex - Hong Kong / British Virgin Islands (BVI)

Planned

• Coinbase/ GDAX - USA

EtherEx will be an open source, non-profit, next generation decentralized exchange built on Ethereum.
Etherex is currently in alpha 

Cryptocompare provide an overview and detailed analysis of the primary exchanges.

Exchanges that support The DAO Tokens

• Currently
  • Bittrex - USA
  • Bity
  • Kraken - USA
  • Poloniex - USA