Certainly Geb, Bekele and Tergat are all up there, as are Nurmi and Zatopek. Coe was an 800/miler. His better range was dropping to 400 rather the going up to 5k or 10k. He was pure middle distance. How would he be that much better then Morceli, El G, or Kipketer? Kipketer had a medal in his pocket if it wasn't for the Olympic Rules.
Anyway, El G is up there, but not top 3. Similar to Coe, not enough range to call him the greatest distance runner ever. One of the best mid-d guys for sure... but his wheelhouse ended at 5k, and he couldn't drop down to 800 like Coe could. Komen is up there, but its hard to actually list him because he didn't have any longevity, and no medals.
So, Geb, Bekele, Tergat, Nurmi and Zatopek are certainly standouts, imho.
How you don't have Geb in the top 3 is ridiculous. 1500 indoor gold through marathon world record. So he wasn't dominant in cross country. Who cares? He was/is on the track and roads and no one in history has showed his range. His ability makes no sense. And for all of Bekele's concentration, its not like he bettered Geb's records by leaps and bounds... he improved them marginally. Geb broke through to a new level. He did what no-one had every done before him. He brought the record from 12:56 (I think) to 12:39! Bekele took it 2 more seconds! What was the WR in the 10k before Geb eventually brought it to 26:22?
Geb broke so many barriers and did it from the 1500 to the marathon. INSANE.