I'm trading on changenow, it's non-custodial trading service. I like that I can trade there without registration and verification. Also, my funds are safe, because they are on my wallet instead of exchange's wallet
I used to trade my altcoin in COSS exchange floor. And I think this exchange floor is very convenient, safe and secure. If you earned tokens from the bounty ICO, I suggest you sell your altcoins is COSS exchange floor to get the highest security for your wallet.