Buses to DTD always take the longest. They have the longest wait times. So, it really doesn't matter which resort you go to.
If you go to SSR, you can get off at Congress (I believe that's still the case now that the new walkway is open) and walk to DTD/ Or, you can go to POR/POFQ and take the boat...very pleasant way to go. Same thing with OKW.
If you want to take the bus, just go to whatever resort is closest to the park you're in.