The is a controversial topic on the many definitions of what you would call accurate. There's the ability to SS a ton of maps, the ability to play maps with mods, streaming, jumps, difficulty, ect.
For example, you could have someone with a 100% accuracy and crapton of SS ranks, but what if the only songs they play are 1 star? .-. Bit of an over exaggeration but apply that to current players.
Cookiezi is known for constant S-ranks, doubletimed songs, and holding out combo's the best. Mesita(from what I've seen) uses the flashlight a ton, and is very good at it. How are you supposed to decide who's the better player based off doubletime or flashlight, the 2 mods are totally different along with the players. Look at Elfice, his accuracy is astonishing, but put on songs like airman it becomes a problem.
So I really have no opinion on the "most accurate" player, if it came down to who is the best player that's pretty obvious. But then again, I've only been here several months as apposed to everyone else xP soooo whatev's.