Not gonna rank them all, but I can tell you which are easiest/hardest off the bat (generally, this is very subjective)
#2 Bb major, #5 G minor, #7 C minor, #9 Eb minor; those are generally known as some of the more difficult preludes. As far as the 'easier' preludes go; the slower ones, #1 F# minor, #10 Gb major; those are probably the easier preludes. The others vary, and IMO are between the two groups. As far as ranking each one, gl with that because it's only valid to do so if you've played them all, and I doubt very many ppl on this forum have.