OED wrote:
I say its Geb. He was an all timer in every event from the 1500 (would have set the WR in the indoor 1500 but El G outkicked him) to the marathon. He set 27 world records.
I think the key for me is that he came along and took the 5 and 10 records into a whole new realm that 25 years later only two guys have bettered. He ultimately dropped the 5k WR by 19(!) seconds and the 10k by 30. Bekele only dropped them by 2 and 5 seconds, respectively, which to me shows how much more dominate Geb really was.
Only problem with that logic is once Geb brought the record down to 12:39.36, it was not reasonable to expect someone else to better that improvement by dropping 20 seconds from his record. That would mean running 12:19!
I think a better gauge is world record duration. Geb was trading the 5,000 record back and forth with others, which shows he was not peerless. Bekele’s records lasted much longer, and he would still have those records if it wasn’t for super shoes and pacing lights. Plus Bekele had the cross country dominance that Geb never had.