I beg to defer, I have taken the Rapid air-cond bus in Penang from the ferry terminal to kek lok si..it was suprisingly cleaner , cooler & better than that of SINgapore..
KL..ahhh it varies...even JB some of the public transport buses are quite ok...
You said it..."some", not all
Its the same for public busese in Singapore.
I dun deny i cant tolerate some public buses myself but in general, its only for awhile and not for like.....5 hours. its still quiote fine to ride in them.
and besides, some time the smell is not the fault of the bus or the driver, but the inconsiderate passangers.