There is an active discussion about exchanges and a list of current and dead bitcoin/altcoin exchanges now at
https://bitcointalksearch.org/topic/altcoin-exchange-list-list-of-altcoin-and-bitcoin-cryptocurrency-exchanges-777154
Thanks this list is the most complete one i have seen so far.
Normally i check here for the most active exhanges:
http://coinmarketcap.com/currencies/bitcoin/#markets
I added another column to Minkiz' listing, an orange check mark to indicate that the exchange appears in coinmarketcap's list.
https://minkiz.co/exchange
I've restructured the representation slightly, switching the located-in-jurisdiction field from ISO 2 country codes to the latest ISO country “profiles”.
For general consumption, I created a small supporting ontology CCE (CryptoCurrencyExchange) for an initial formalisation of the terms and added it to the DOACC project. The listing of individuals is published separately in the DOACC repository.
The methods, tools etc described in the DOACC documentation apply equally to CCE.
HTH
Cheers
Graham