I don't which one is the  best ICO of 2018 and it is too early to say it
 but you should take a look at Myriads.IO project.
It is about decentralized machine learning network. Myriads network offers an opportunity to earn MRDS tokens from useful calculations. Any GPU can make machine learning computations.
Myriads network generate tasks for miners and provide predictions.
Number of MRDS token in existence strictly limited by algorithm.
The ICO didn't start yet so it is not too late to join
If you want more details, you can check their website : https://myriads.io