There are many characteristic of good ICO. But to check almost all of them you need to spend a lot of time and have patience. The most important thing is to be sure that ICO is not scam. To be honest you never can e sure in 100%, because sometimes ppl spend millions dollars to achieve more. And their ico looks good enough to investors.
1. Looks at the team, each members play role. Discover their background, education, professional skills. Members should have prefect reputations.
2. White paper - the main document of ICO. There you should find all details about development and implementing stage of project, description of idea and all ways to use product, amount of money step by step.
3. Web-site, social support in all resources that you can find.
4. Good but not necessary to have a demo version of your product.
5. Bounty campaign and promo activities should take not more than 10% of all tokens, in my own opinion
6. Road map with understandable and real stages.

Due to this reasons i choose Confideal. There ICO will start in 2 days. Please take a look - https://confideal.io/