Interested to find a good resource with all active bitcoins exchanges
Cryptonator looks like a good start. 
Find all exchanges for a particular trading pair. 
https://api.cryptonator.com/api/full/eth-btc

Then swap out the eth with whatever currency you're looking for. 

Cryptonator says this is all their supported currency pairs (https://www.cryptonator.com/api/currencies) but looks like it includes some dead coins. You could loop through that URL and for each record, input the symbol into the original https://api.cryptonator.com/api/full/eth-btc end-point.

https://api.cryptonator.com/api/full/ltc-btc
https://api.cryptonator.com/api/full/dash-btc
...and so on.

Once the loop is through you should have all pairs and all currencies, or at least all the ones cryptonator has.