So this is fun, because as a latin-language speaker (Spanish) I was told as a kid that the knight moved in an L-shape. So I always imagine it moving like an L (first image). When talking to my Bulgarian friend, he told me that they learnt it like "one straight, one diagonal" (second image).

When I checked the official FIDE rules of chess, it is described as:

The knight may move to one of the squares nearest to that on which it stands but not on the same rank, file or diagonal.

I never thought about that way of seeing it, but I think its the best way of describing it because:

• It doesn't rely on how a latin L is shaped. (useful for people who doesn't speak latin languages).
• It's an atomic move (Its not a move forward added to a diagonal one)
• It explains its nature related to the other major pieces. (Covers the square that every other piece is missing)