I got to say R.C. Buford, Spurs. Done it way too long found a way to keep the young talent rolling right in with the vets and winning four championships. Morey would be my #2 Sam Presti from OKC would be my #3, mostly he's just had the pleasure of drafting high in the lottery but the Perkins trade was masterful.
FWIW, It was Pop who really set the foundation for the Spurs' run. He was the GM from 94 to 02, and then he gave the title to Buford. Technically, Buford's "only" won 3 rings as GM. The Spurs just have Pop written all over. I can't give Buford that much credit as GM.
I think Pop & RC Buford should be considered as one person. They communicate with each other with everything.
They complemented the two max salaries he inherited. Answer the question though Major....is that supporting cast better or worse than the pre-Morey era? Was it better when it was Rafer Alston, Scott Padgett, Kirk Snyder, and Ryan Bowen complementing the Yao-Tracy nucleus, or was the team better off with Scola, Landry, Brooks, Lowry, Artest, Wafer et al? The answer to this is pretty easy for most Rockets fans to figure out.