What are the best magical systems in GURPS?

[AlexanderHowl]

I am curious what people consider the best magical systems in GURPS? I consider RPM to be the overall best system because of its features, though I tend to customize the Core Skills and Paths to the individual settings. After RPM, I am fond of Path/Book magic because it is subtle, especially in settings with secret magic. After Path/Book magic, I find that I enjoy Verb/Noun magic, as it is probably the most flexible system of magic in GURPS, and it lacks the very high point investment of Realm Magic.