Eliud Kipchoge coming in at Berlin at 2:04:05 strikes me as super-impressive. That puts him ahead of Paul Tergat at both 5k and marathon lifetime PBs. As far as range and success at long-distances, looking at both track AND road, where would he rank?
My vote:
1) Geb -- one time record holder in 5k, 10k, HM, marathon, and a ton in between
2) Tergat -- maybe the first of the great track-turned-roads guys, also all the XC championships
3) Kipchoge -- 5 championship medals, 12:46 5k and 2:04:05
4) Bekele -- obvi 12:37--HM is unparalleled, but unproven at marathon. It pains me to put Kipchoge ahead here, but he has the better record if you're looking at track and road success. If this were "greatest track distance runner of all time," obviously Bekele would be #1
5) Mo Farah -- 3:28 to 1:00:10 is obviously impressive but unproven entity on roads.
6) Tadese -- medals at a ton of distances, but behind the others because he's so optimized for the HM, no world class marathon to show for it.
Thoughts?