Sinclair without question. Schelhaas is competent but I've always found him to be fairly average and occasionally, below average. Listen to his scrappy solos on live DVDs like 'A Knight In London' and wonder how he ever got into such a classic band. However, to be fair, that DVD caught everyone on an off-night and the band didn't even get paid royalties for its release! He was largely very good on the 35th Anniversary Concert DVD.
I must say Sinclair was one of the best during the early 70s but his returns over the years were rather less impressive. I sensed a lack of commitment to what he was playing on some performances I've seen and heard on DVD etc. Still, based on his 70s output, it still has to be him.