In my personal Foldit history, I've seen very few "world n° 1" solo players. Here is a list of identified rank 1 players in History:
mimi (also #1 solo and evo at same time, I believe)
Galaxie (who even ever got rank 1 evo and solo 1 at the same time)
Timo Van Der Laan
LociOiling (who even ever got rank 1 evo and solo 1 at the same time)
mirp (who even ever got rank 1 evo and solo 1 at the same time)
May I ask to the oldest players if they can add players to this list for the time before 2014 ?
Maarten desnouck started collecting top player's daily score data from 8 apr 2014 to mid 2017. I could copy some of his data and update it for latest years.
(note that the ranking in the past is not correct, because old top players disappeared from the chart, for example ZeroLeak7 who was rank 1 most of early 2020).