It is impossible to peg a 100x just like that but one should look for projects similar to those in the top 50 and look for projects that can do similar. This Pearl coin as of late has surged massively and I think it is a safe bet to be at least 100x if you got in early. Other than that for me it is too early to tell what is going to moon like madness in 2018.
Always look at coins that are fairly low on the ranking list, have high volume and a decent roadmap. I for once like
Aventus, listed around rank 300 with a market cap of around 35 million. Listed on BitFinex is expected to announce collaborations with ticket companies soon.