Originally Posted by
Ryvyan
My friend said that the Metro is the cheapest, so to try and use them as much as possible. Transferring to different lines is okay, but can be pricey if it includes Toei because it is the most expensive.
JR Lines are not too pricey but very busy because it covers a lot of suburb areas; I stayed in Mitaka and tried to avoid peak hour rush as much as possible.
I'd say that the Tokyo Metro and JR have the bigger footprints in the Tokyo area. They both cover a lot of ground. However, there are differences between them in what they connect to. For example, JR does NOT go to Roppongi or Asakusa while Toei and Metro lines do. JR is often more direct as the crow flies between major points (Tokyo to Shinjuku or Narita to Tokyo/Shinagawa/Shibuya/Shinjuku for example) and has the all purpose Yamanote loop line. If you look at a subway map, you'll see that the lines rarely go in a straight line, instead taking a crooked route to serve as many areas as they can while avoiding the Imperial Palace.
Knowing this is useful to plan your days and so you're not surprised when you have to transfer to different lines. Best advice for a visitor: don't worry about having to switch about. People there do it every day. And you'll get a taste of local life too.