Hagoromo
Madara
Obito
Nagato
Sasuke
This is purely based on their mastery, not just how many rinnegan jutsus they can use, allow me to explain.
Madara awakened the rinnegan after the sage, he then read the uchiha tablet which presumably had the rinnegan jutsus inscribed on it [otherwise how did madara even find out about some of the jutsus?]. He knew the juubi's coffin seal & limbo, only he knows limbo & obito is the only other one to know the seal.
Then madara taught everything he knew about the rinnegan & it's jutsus to obito, who knew the coffin seal, could control the GM effortlessly, & has a better mastery over the outer path than nagato does.
Then obito taught nagato, who was able to learn every rinnegan jutsu thanks to having both eyes. However knowing every rinnegan jutsu doesn't make you a master at using it because obito still showed us better rinnegan feats with the paths he was limited to.
Sasuke learned a few rinnegan jutsus on his own, & the few he's shown us surpass nagato's feats [more than one CBT/absorbing the bijuu chakra into a pseudo GM]. But since sasuke lacks the experience that the others do with the rinnegan his mastery is slightly behind theirs, since he should logically have access to all the rinnegan's jutsus.