I enjoy comparing baseball and football:

Baseball is a nineteenth-century pastoral game.
Football is a twentieth-century technological struggle.

Baseball is played on a diamond, in a park.The baseball park!
Football is played on a gridiron, in a stadium, sometimes called Soldier Field or War Memorial Stadium.

Baseball begins in the spring, the season of new life.
Football begins in the fall, when everything's dying.

In football you wear a helmet.
In baseball you wear a cap.

Football is concerned with downs - what down is it?
Baseball is concerned with ups - who's up?

In football you receive a penalty.
In baseball you make an error.

In football the specialist comes in to kick.
In baseball the specialist comes in to relieve somebody.

Football has hitting, clipping, spearing, piling on, personal fouls, late hitting and unnecessary roughness.
Baseball has the sacrifice.

Football is played in any kind of weather: rain, snow, sleet, hail, fog...
In baseball, if it rains, we don't go out to play.

Baseball has the seventh inning stretch.
Football has the two minute warning.

Baseball has no time limit: we don't know when it's gonna end - might have extra innings.
Football is rigidly timed, and it will end even if we've got to go to sudden death.

In baseball, during the game, in the stands, there's kind of a picnic feeling; emotions may run high or low, but there's not too much unpleasantness.
In football, during the game in the stands, you can be sure that at least twenty-seven times you're capable of taking the life of a fellow human being.

And finally, the objectives of the two games are completely different:

In football the object is for the quarterback, also known as the field general, to be on target with his aerial assault, riddling the defense by hitting his receivers with deadly accuracy in spite of the blitz, even if he has to use shotgun. With short bullet passes and long bombs, he marches his troops into enemy territory, balancing this aerial assault with a sustained ground attack that punches holes in the forward wall of the enemy's defensive line.

In baseball the object is to go home! And to be safe! - I hope I'll be safe at home!