Most AOs in the Open Era 4...
Tied with Sampras and Connors in USOs with 5....
One behind Sampras in Ws (7 vs. 6)
Five behind Borg in FOs (1 vs. 6)
I think he'll win another AO, 2 more Ws, and another USO, for 20 overall (5 AOs, 1 FO, 8 Ws, 6 USOs). Then he'll have the most AOs, Ws, and USOs. FO, Borg can have that one.
More impressively, if he wins the French this year, which he has a decent shot at doing, he'll be the only player to win each grand slam in back to back years. Now that would be something.