Here’s an interesting nugget of League of Legends eSports information: GameSpot interviewed a bunch of North American pro players and found that an overwhelming majority would prefer the League Championship Series (LCS) format be changed to best of two games, rather than best of one. I think they all have a point.
Best of two? Meaning the first team to win two? Isn’t that usually called best of three?
Anyway, in general I'd agree that series usually work better than single eliminations. Lets luck and that sort of thing filter out a bit and, ideally, make skill a bigger determining factor.