S1mply the best, he outclasses everybody if you look at his stats AWPing against good teams on LAN. Just what he does for his team is insane as well, he's the best in the world. He's an AWPer. S1mple as that. He stands out from the rest of his team.
Guardian has been a very consistent AWPer, hitting his shots etc. Still though, he isn't the nr.1 player in his team, he isn't the main focus. And doesn't really stand out from his team. Therefore it's pretty much impossible to get as much impact as S1mple. So I'd say he's number 2, just barely.
3. Device - Has had a great year, but he still doesn't reach the level of Guardian or S1mple individually with the AWP. Therefore as an AWPer it's hard to put him above these 2.
He carried the heck out of this new G2 lineup during the last few events, I'd consider him one of the top AWPers. But to reach higher this G2 lineup would have to accomplish something big, which they haven't done.
This should normally be Oskar's spot, but he has been in somewhat of a slump recently. He needs to get back to form. Cerq has proven a lot but still needs to perform in the really big situations. For example in a stadiuim in a semi final. Draken is too inconsistent to get the positions alone.