The Premier League definitely is currently the richest, and has the best quality of football. I'm a Manchester City fan, so make of that as you will. I have an odd view for football though, personally I can find 0-0 droughts interesting in a sense compared to others. While the quality of football has a heavy tie to the entertainment and value of a league and it's teams, it's not the end all be all. Lower league football is very entertaining at times compared to the top flight.
Other teams I support are LOSC Lille (Ligue 1), Inter Milan (Serie A), and Seattle Sounders (MLS (I honestly chose to support this team on a whim but grew to like them quite a bit)).