Never realized LA actually had a system. I thought it was cars and cars alone with buses being Z grade.

Another one that is worth seeing is the Moscow one. The old part (1930s vintage) is actually quite beautiful - lots of artwork, mosaics, etc... Communist art, but still well done. The "newer" part (1960s) is New York industrial style without the quality. Definitely an easy way to get around, and they have coloured lines as well as numbers/letter, making it easy for tourists to figure out where they are going. Main advice would be try to get a small grasp of cyrillic writing so you can at least recognize what station you are at.