Here's an year old article i found, so it wont include some 1st and 2nd year rookies.
Hayes, Green top list of NFL’s fastest ever
By Joel Buchsbaum, Contributing editor
As published in print Sept. 24, 2001
Some players have what is known as football speed. Others have track speed. Some have both. In his prime, Darrell Green may have had the best combination of the two. Jerry Rice, in his prime, never ran under 4.5 seconds in the 40-yard dash for the stopwatch. Yet in terms of football speed, he was about a 4.3 guy. On the other hand, Eddie Kennison won races that made him the NFL’s fastest man in gym shorts. But after he puts the pads on, he rarely shows that type of speed on the field. With this in mind, we asked NFL insiders who they believe had the best combination of track and football speed. (List only includes post-merger players.)
1. Bob Hayes / Cowboys – "World’s fastest man and fastest football player in his prime."
2. Darrell Green / Redskins — "Nolan Ryan was throwing 100 mph when he was over 40 (years old), and Green was running sub-4.4 (in the 40) and still running with all the racehorses."
3. Cliff Branch / Raiders and Mel Gray / Cardinals (tie) — "Both were diminutive sprinters no defensive back could stay with. If they were close to even, they were leavin’, and you needed to keep a seven- to 10-yard cushion against both or else they would eat up your cushion and be by you before you could react."
5. Bo Jackson / Raiders — "Before his injury, he was the fastest big man I ever saw. However, he still was more track- than football-fast."
6. Randy Moss / Vikings — "If he trained for it, he could be a world-class sprinter."
7. Wesley Walker / Jets — "A true jet."
8. Homer Jones / Giants, Browns — "A king-size receiver who could run like a deer."
9. Deion Sanders / Falcons, 49ers, Cowboys, Redskins — "Rare playing speed and excellent but not great track times."
10. Rick Upchurch / Broncos — "Could go from zero to 60 like a race car."
Others mentioned: Stanley Morgan, Lance Alworth, Isaac Curtis, Willie Gault, Jimmy Johnson (49ers), Willie Buchanon (Packers; before injury) and Eric Dickerson.