Comments are off the top of my head when last used, not very scientific, just markets I've used lately. * gdax.com - coinbase's exchange - only btc/eth/ltc, easy to buy with CC, high fees, high traffic * etherdelta.github.io - only erc20 tokens, contract based, low fees, very bad ux, low traffic * kraken.com - quite a few alt coins and tokens, insanely slow support, bad ux, average to high fees, average traffic * hib…
-Which have (legal) US compliance?
-Which have options/futures or other contracts?
-Which have red flags (holds on withdrawls for mysterious reasons, like Poloniex, for example)
-Which have security red flags?
-Which have actual support help?
-What countries are they based in?