I look at:
Talent, especially how likely it is that he has elite talent.
Situation/opportunity, especially how good the team's QB is and whether they already have an established go-to receiver.
Based on that, I'd rank the top 3 options as D.J. Moore CAR, Mike Williams LAC, and Calvin Ridley ATL. All 3 have the potential to be elite talents, Carolina doesn't have a go-to receiver yet, and Rivers & Ryan are both good enough to support multiple high-end receivers.
As the next batch I'd put (in order): Michael Gallup DAL, Tre'Quan Smith NO, Taywan Taylor TEN, Courtland Sutton DEN, Chris Godwin TB, Kenny Golladay DET. Most of these guys are mid-range prospects in terms of talent who are in a pretty good situation due to their QB (NO, TB, DET) or lack of an established go-to receiver (DAL, TEN). Sutton has more upside in terms of talent but has a worse situation.