Firstly this depends on your risk tolerance. Without understanding more specifics behind the case (your investment knowledge, trading ability, etc) I would say at a high level best to diversify across a basket of the top 10 cryptocurrencies by market capitalization.

ICOs are exciting, but it is still a nascent territory and you need organizational timing (ensuring you are whitelists), smart execution (selling out of your positions) and be spread across a number of bets (diversification) to make it pay off. Also there is uncertain regulatory and tax compliance risk, depending on your jurisdiction.

Hope this is somewhat helpful, given the limited information you provided