Mike Will. After he used the low-pass filter in Way Too Gone everyone started doing that shyt. Lex's run was pretty epic though. Maybe throw Southside in there, because he was right beside Lex doing the same shyt and he evolved and is still around today.
Really though look at production and the whole state of VA has had the best run over the course of time. Teddy Riley -> Timberland -> Neptunes -> Lex. And that's just the bigger guys. Guys like bink, nottz are from VA too. the state of VA has had the most lowkey impact on rap music out of any area
This.
Timbaland's run often gets overlooked in favor of The Neptunes, but he actually had a longer and arguably bigger run. From 1996-2008, we're talking about:
If Your Girl Only Knew- Top 20
Pony - Top 10
One In A Million- Top 25
Sock It 2 Me- Top 20
Up Jumps Da Boogie- Top 20
What About Us- Top 20
Are You That Somebody- Top 25
Make It Hot- Top 5
So Anxious- Top 20
Hot Boyz- Top 5
Big Pimpin'- Top 20
Try Again- #1 hit
Get Ur Freak On- Top 10
Ugly- Top 20
Raise Up- Top 20
Roll Out- Top 20
One Minute Man- Top 20
More Than A Woman- Top 25
I Care 4 U- Top 20
Oops (Oh My)- Top 10
Work It- #2
Gossip Folks- Top 10
Cry Me A River- Top 3
The Jump Off- Top 20
Dirt Off Your Shoulders- Top 5
Headsprung- Top 10
SexyBack- #1 hit
My Love- #1 hit
What Goes Around- #1 hit
Lovestoned- Top 20
Until The End of Time- Top 20
Summer Love- Top 10
Promiscuous- #1 hit
Say It Right- #1 hit
AYO Technology- Top 5
Make Me Better- Top 10
The Way I Are- Top 5
Give It To Me- #1 hit
Apologize- Top 3
That's not even counting the albums he either helmed or entirely produced that went platinum and multi-platinum.