Tips? For finding a competitive online league?

I've been playing exclusively in Yahoo! leagues (both public and
private) for the past three years, and the quality of the competition
has varied widely, regardless of whether or not the league is billed
as "competitive".  How can I ensure that the leagues I join next year
have active managers (for the first several months at least)?  Do I
need to join leagues that require fees?  Start my own league?