You can check any of the ICO review sites (such as ICO bench, icorating.com and ICOstamp), and the first thing you may notice is that the number of ongoing ICOs have come down quite drastically over the past few months. According to the ICO bench website, till date we had more than 5,000 different ICOs, but only 52 are listed for this month. For comparison, we had an average of 200 to 300 per month for 2018.
Some of the recent ICOs (of 2019), that have given a good ROI include Pledgecamp, EMOGI Network, Wink, Akropolis, Elrond Network and Sero. In percentage terms, the record belongs to Volume Network, which gave 453x returns since its ICO (in May 2019). But it was a very small ICO ($30,000 was raised in total) and we can't regard it as a benchmark.
How is it possible for an ICO to give 45,300% returns? Are you sure about your figures? Can anyone confirm this post about the Volume Network ICO? The claimed returns are just insane. If there are such ICOs ongoing now, then it may still be worth the risk to invest in them. Even if we invest in 100 ICOs and get one ICO with 453x return, then that alone is enough to get a positive ROI.