Lifetime Longhorn Rod Babers researched and wrote a piece for 247Sports in which he lists the best DBs in Longhorn history.
This list was comprised with an emphasis on All-SWC and All-Big 12 selections, All-American selections and the player's impact based on stats. I, of course, made the last call.
The Mount Rushmore of DBU:
1. Jerry Gray (One of the patriarchs of DBU and had the legendary Jheri curl)
2. Johnnie Johnson (Two-time consensus All-American and would've won Thorpe Award if it existed)
3. Michael Huff (Consensus All-American, Thorpe Award winner and a national champion)
4. Nathan Vasher (The only DB at DBU to be an All-American at two different positions)
The All Americans:
5. Earl Thomas (If he stayed four years he'd be on the Mount Rushmore; school single-season interceptions leader)
6. Aaron Ross (Winner of the Thorpe Award in 2006 as the nation's top DB)
7. Quentin Jammer (Consensus All-American, responsible for making DBU relevant again)
8. Lance Gunn (Most would say he's too high, but he's a three-time All-SWC player and an All American)
9. Bryant Westbrook (Two-time All-SWC player and an All-American)
10. Noble Doss (Tied as career interceptions leader, never was All-American or all-conference)
11. Raymond Clayborn (Two-time All-SWC selection and an All-American)
12. Stanley Richard (“The Sheriff” was All-SWC and an All-American in 1990)
13. Kenny Vaccaro (First-Team All-Big 12 performer in 2011 and 2012, plus an All-American)
14. Michael Griffin (An All-American and First-Team All-Big 12 selection in 2006)
15. Mossy Cade (All-SWC and All-American; big impact on stats (top-ten in career interceptions)
16. Bobby Dillon (One of the founding fathers of DBU; All-American in 1951)
17. Rod Babers (All Big-12 and All-American in 2002; fourth all-time in career and single-season PBUs)
18. Quandre Diggs (Second-Team All-Big 12 twice, once Honorable Mention All-Big 12, Freshman All-American, ninth in career interceptions (11), ninth in career quarterback pressures (36) and 10th in PBU's (36))
19. Curtis Brown (Honorable Mention All Big-12 and Honorable Mention All-American in 2009, Second-Team All-Big 12 in 2010)
The Rest of the Best:
20. Chris Carter (Fifth in career interceptions; All-SWC in 1995)
21. Jack Crain (Two-time all-conference selection, tied for second in single season interceptions)
22. Derrick Hatchett (Fourth all-time in career interceptions; All-SWC in 1979)
23. Cedric Griffin (First-Team All-Big 12 selection in 2005, Honorable Mention in 2004)
24. Blake Gideon (Four-time All-Big 12 Honorable Mention, started more games than any player in UT history)
25. William Graham (Tied for second in single-season interceptions and tied for ninth in career interceptions)
26. Van Malone (All-SWC in 1993)
27. Stephen Bragg (All-SWC in 1986; Six interceptions in one season in 1986)
28. Aaron Williams (Not here long enough to make big impact; Second-Team All-Big 12 in 2010)
29. Vance Bedford (Two time Second-Team All-SWC, fifth in career PBU's and third in single season PBU's)
30. Marcus Griffin (Younger brother of Michael Griffin, First-Team All-Big 12 selection in 2007)
[See the rest of his 56 listees and read the article here]