If my top 150 list is accurate, the Big Ten has the most high-end talent. By quite a bit, actually. Here are the top 30 players by conference. I probably overvalue the mid-majors a bit. I could realistically see Merrill, Ford, or Aiken making an All-American team, however.
Big Ten (7)
1. Cassius Winston, Michigan State
8. Jalen Smith, Maryland
14. Lamar Stevens, Penn State
17. Ayo Dosunmu, Illinois
26. Zavier Simpson, Michigan
28. Kaleb Wesson, Ohio State
30. Anthony Cowan, Maryland
SEC (4)
13. Kerry Blackshear, Florida
18. Anthony Edwards, Georgia
20. Tyrese Maxey, Kentucky
23. Andrew Nembhard, Florida
Big XII (3)
5. Udoka Azubuike, Kansas
10. Tristan Clark, Baylor
11. Devon Dotson, Kansas
ACC (3)
4. Jordan Nwora, Louisville
6. Cole Anthony, North Carolina
12. Tre Jones, Duke
Pac-12 (3)
16. Nico Mannion, Arizona
21. Tres Tinkle, Oregon State
29. Isaiah Stewart, Washington
Big East (2)
2. Myles Powell, Seton Hall
3. Markus Howard, Marquette
AAC (2)
7. James Wiseman, Memphis
9. Jarron Cumberland, Cincinnati
Mid-Majors (6)
15. Antoine Davis, Detroit
19. Sam Merrill, Utah State
22. Jordan Ford, Saint Mary's
24. Anthony Lamb, Vermont
25. Lamine Diane, CS Northridge
27. Bryce Aiken, Harvard