AKL only shares bus service with Kidani Village. I don't know how often SSR or OKW share bus service, but there are multiple stops in each resort.
Except the biggest variable isn't bus route, it's waiting time. The bus routes vary from what is shown in the guide. Off peak, I've been on buses which go to all the EPCOT resorts. I've been on buses which include Contemporary, POLY and GF. I've been on buses which made all the stops in both OKW and SSR.
You're concerned with transportation. A taxi will always be faster. Taxi to BLT if you're going to the MK. Contemporary has the best transportation to the MK (walk) POLY and GF next best, monorail and boat. The EPCOT resorts (BC,YC,BCV,BWI,BWV,Swan and Dolphin) have the best transportation to EPCOT and DHS (boat or walk).
POP has the best bus service. Non-stop bus service. AoA is also good. AKL isn't bad. All other resorts have multiple (maybe many multiple) stops in your resort and/or many resorts.