I always liked the KMB (Kowloon Motor Bus) coaches in Hong Kong...especially the old double-deck light yellow ones. I know NOTHING about them, but I find myself waxing nostalgic about the sometimes TERRIFYING experience of catching one and sometimes hanging off the side (this was the 70s and 80s). I still believe HK has the best mass transit I have ever seen...and is MUCH more efficient than owning any car.
San Diego and L.A. are so weird and complicated. I've only tried to brave mass transit here in the states a couple times.....and it's MUCH too complicated to work.
I have seen diecast models of them...but refrained from buying even ONE, or it would become a collection as well