In European Football (soccer), teams in the top league have 3 championships to play for every year:

1. League Championship
This competition is round-robin (home and away) with every other team and is decided by the final record (points). It is equivalent to the "regular season" in US sports (if all regular seasons were balanced).

2. National Championship Tournament
Each country holds some version of a national championship where ALL teams qualify for the playoff-style tournament. It usually takes months to play out and "Division 2", "Division 3", etc. all participate and occasionally get games with the "big boys" in Division 1. Of course, the champion is usually a top-division team (beating other top division teams at the end). This is a "winner advances, loser is eliminated" in each game playoff style tournament.

3. Continental Championship (a.k.a."Champions League" in Europe)
Every European Top League Champion Qualifies, plus up to 3 other "at large" teams in the highest rated conferences (decided on final rankings - no committees) play in a cross-continent hybrid tournament. In the early rounds, "divisions" are created with round-robin play and the top teams in each division move onto a playoff round. Each round of the playoffs (except the final) is a two-game elimination match based on total goals scored. The finals is a one game winner-take-all.

The really cool thing about this is... all of these championships are competed at the same time (during the league's "regular season"). The league championship is celebrated as much (if not more) as the "playoff tournament" championships. Yes, only in America do we dismiss the accomplishments of a regular season championship if that team fails to win the subsequent playoff tournament. European soccer celebrates all of these championships.

The net effect is that there seem to be meaningful games all year to get points in the league standings or advance in one of these tournaments. It's a very cool system. But sadly, it could not work in American football because the game cannot be played multiple times per week.