Binance is the one at the moment. Everything on there is mega-hyped, so its probably good for buying and then selling quickly, but I'm not so sure about long-term strength of these coins. It reminds me of how ICOs used to be a couple of years ago, when so many coins hit hard cap really quickly.
But the big problem is in BNB. At IEO Wink, many investors lost big money when buying BNB at $ 33 and received quite a few winning tickets. Many people lost more than $ 5k because the price of BNB decreased.
Currently I see the IEO in Binance is quite risky. Huobi is safer when it has kept prices higher than 4.3 for several weeks now.