1961 Bama -- not the best team, maybe best season, but not best team
There are a number of better teams.
Personally i never saw one better than:
1980 pitt, best college football team ever.
25 players on the roster that year were starters in the pros and a number of HOF'ers. If not for a game in a florida monsoon it would be common knowledge(against fsu, who's coach agrees this pitt team was the best he ever saw).