i think the best route has been clear for a time now. i have to thank you for all this data gathering, which kinda just confirms people's speculations.
now to share my personal experience, feel free to cross reference with the data from OP.
southern highlands-->cave of the moon clan 1&2. (best in my opinion if you want to farm a single place over and over, rush to cave, dont scout rest of the region)
cathedral level 1--->leoric's passage (semi scout cathedral, if you find leoric's passage entrance just enter it and skip rest of cathedral)
northern highlands (scout whole region, chance for 0-2 goblins)
pandemonium fortress level 1 (if you hear or find 1 goblin, then there is ALWAYS a second one in the floor)
in my opinion these 4 are the ones you should spam, fairly high chance for goblin(s) without being as mind-numbing as doing a single run over and over again. now if you hate remaking game you can add some more.
royal crypts--->core of arreat (these two are so small you can just go in there and have a quick look)
tower of the damned 1&2 ( people swear about this place, my results,rng, lack of data or whatever you want to call it, tell me its not that good)
gardens of hope 1 (this is a place that is always in my goblin route, while some people dont really like it)
ancients waterways west-east 1&2 (other people's favourites, fairly average for me, i go sometimes when i get bored)
now cross my post with the data our friend Chibosader gathered and find your own best route that suits your playstyle, speed, or most fun for you to run.