Questions...

How far will be riding regularly?

Do you need the bike for commuting by train at all?

When you say joy ride, is this for leisure or speed (one person's joy is another person's pain after all)?

Does size matter? Are you trying to get something that will fit in a small apartment or office?

Based on what you've said so far, I wouldn't necessarily recommend a folder. You might be better off with a typical commuter bike. But yeah... if you're dead set on a folder answering the above questions will help narrow things down a little.

--sam