If you can turn injuries off, the best backs I've ever seen at Miami in my lifetime (started going to games in 1989) was:
1. Frank Gore
2. Willis McGahee
3. Edgerrin James
4. Clinton Portis
The ONLY caveat here is, we didn't get to see Frank do it as a starter against good comp. But I don't care, that 2001 season, he was literally breathtaking. You guys gotta remember, this was pre-internet, for the most part. It existed, but it was 0.0001% the way it is today. So there were plenty of people going to the games who knew who Frank was and what he did at Gables. But the vast majority of people in that building did not. So when he came into the game and got his first carry, you could literally feel 50K people gasping. It was insane. He was shot out of a ******* cannon, with lateral agility I've rarely seen from anyone, ever. So if you wanna say he wasn't #1, I get it. The other guys definitely did more against good teams, by the time Frank rehabbed to become the starter, he wasn't the same player as he was as a true freshman. But to me, again this is all assuming injuries never happen, that 2001 season from Gore was one of the best running backs I've ever seen in person, at any level from any team. He was literally breathtaking.