In my personal Foldit history, I've seen very few "world n° 1" solo players. Here they are, as I can remember:
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)
Historical data starting 8 apr 2014 are available here:
May I ask to the oldest players if they can add players to this list for the time before 2014 ?