I want to ask you that, knowing this! what will u get?
Lets say its rapha, so what? he does it for himself, not for you, or another person, ok maybe his sponspors get something from it, but definitely not you!
This is just wrong question on many levels. There is no such thing as "best item timing" (although you can easily say when someone is lacking in this department).
Maybe strongest map control? It's hard to tell too. All pros have strong map control and on maps like dm13 or dm6 it often comes down to aim not timing. On the other hand many semi pros have weak map control but strong out of control aim-whoring game.
I can time 4+ items consistently. Does this put me on the list among rapha and agent? I don't think so.
timing an item on itself is nothing without action in respect to the information you acquire and generate.
backsteen, evil and cooler i think are the 3 players who win alot of situations by just being on the spot in the right second and wining the item. They all do some crazy steals.
rapha on the other hand plays with more room around him, so he always has a couple of scenarios to act upon when he needs to react. When the item is up, he will be near, but not going for it crazy style and puting it all on the line like evil.
other top players all time fine, but its what you do with the information is important. Avek for instance was always a good timer, but all he did was show up at the right time and battle it out. he played it straight and simple and its what kept him from being #1 in alot of tournaments. Rapha cooller, and cypher, they all mess with you in sneaky ways and its part of their personality to think this way, when its just not in aveks honest nature to play that way.