Any league with lots of people is good. One car leagues are more fun & challenging as you can imagine 32 people fighting to get into the top 10 for points
(just an idea to make things more fun in one car leagues)
Team up with someone else, pick a team name and car design between you, then toss a coin see who is [team-name]driver 1 & [team-name]driver 2. League structure isn't set up for it, so you would have to keep a record of points in the forums here.