If you ask me which player I would rather have on my team it would be Darrell Green every time.
If you ask me which player was more talented, I would say Deion Sanders.
If you ask me which player was the better in coverage, I would say Sanders by a slight margin.
If you ask me who was the better overall CB I would say Green was.
For those who state emphatically that Deion was the best CB ever to play I would say that you haven't seen the best then as I could name 5 guys who I saw play that were better CBs than Deion: Herb Adderley, Mike Haynes, Dick Lane, Mel Renfro, and Lem Barney were all, IMO, better CBs than Deion in that they could cover consistently, made plays, and were solid tacklers.
Were they as fast as Deion, no. Could they close on the ball like he could, no. But they also didn't let players get past them or give up long runs because they were afraid to tackle guys (see Ricky Williams vs Deion).
For those who say that teams were afraid to throw against Deion I would say that you must not have been a Cowboys fan in the early 90s since Aikman routinely threw against Deion and completed passes to Irvin and Harper with regularity against him, and that was in his prime. Mark Brunell also ate Deion for lunch when Sanders played for us. He completed several deep passes to Jimmy Smith and Keenan McCardell over Deion. Steve Young didn't fear him nor did Marino, Favre, or Elway. Even Scott Mitchell ate him up one game with 2 big TD passes to Herman Moore. Deion always struggled against the bigger WRs and the better QBs.
I think Deion was a great cover corner but he was over-hyped by ESPN and Chris Berman and was nowhere near as good or consistent as some believe. He made a lot of big plays but he also gave up a lot with blown coverage, being outmuscled, and missed tackles. He relied too much on his closing speed and while it served him well at times he was also burnt by it too often.
I would also say that Deion was the best threat of any defensive/STs player I have ever seen to score and it was this ability more than any other that earned him his reputation as he scored 22 TDs in his career on: 9-INTs, 9-Returns, 3-Receptions, & 1-Fumble. Those are amazing stats and make him the best defensive/STs threat to score ever! But that doesn't make him the best CB ever.
Lastly, I don't like self-serving, grandstanding players and Deion epitomized that mentality. I never wanted him on the Cowboys and was upset when Jerry signed him, just as I was about signing Terrell Owens. Guys like that are a distraction to the team and are only in it for themselves.
That's my opinion, take it or leave it.