In reply to Ben_Climber:
Do they all have to compete in all disciplines or just in their best discipline?
Do they compete "in their prime" (some of your choices may not have reached their prime yet) or as they are today (tricky of course for one of yours, sadly)?
Do they compete in today's conditions, with today's kit, or in the circumstances that pertained in their time?
And you don't say how many must be female. If just one then I agree it would be tricky not to pick Lynn Hill, though Catherine Destivelle might be preferred if they must all do all the disciplines.
If you asked them all to compete with the kit and in the conditions that pertained in, say, the 50's then I doubt if any of your choices would out-compete Joe Brown.
Martin