Absolutely, ICO is the best investment in cryptos world, let me take you back when ETH was doing their ICO in 2014.
The Ethereum ICO lasted for 42 days and went on from July-August 2014 and raised >$18 million. if you invested just 1 BTC you would get 2000 ether in return. The current valuation of those 2000 ether is ~$420,000. Not bad for a $2500 investment! But more than the ROI the biggest thing that makes this particular ICO so important in crypto history is the concept of the project itself.
Invest if you have the privilege in a better project.
Not really advisable if you have weak hands. Playing in this market is really hard. Weak hands would eventually leave just like most of the dumpers. As you can see, altcoins are far more volatile and it is much harder especially for those starting ICOs out there. There will eventually be a problem every now and then. From what I see, I think you should invest in something that is backed by bigger hands. Good projects, nice whitepaper, clear goals, and great developing team. These projects are mostly worth taking on and putting your hard earned money to support.