I would suggest the Fantasy F1 game on http://www.PFRL.net. At the first sight, it looks a little bit complicated, but it has a sophisticated gameplay. Easy to play (just a few seconds to create a team), but hard to win. It’s fun during the whole season.
I play the game on PFF1.net for several years. It’s a quite detailed Fantasy F1 competition.
I have been playing the Fantasy F1 game on http://pff1.net/en/ for a few years.
It’s a free challenging competition. Interesting till the end.