Ideal Anime Season/Arc Length?

It really depends on what kind of arc it is. is it a filler arc? an arc that involves a long epic war? an arc that focuses on a mystery?

• 24-26 total episodes
• 1 overall arc/goal
• 6-7 episode mini-arcs
• Major conflict resolutions by the 12-13th episode and, of course, again at the 24-26th episode
• 1 or 2 filler episodes are acceptable, but preferably none at all

Goku looks so sad. I'd say 24-26 episodes, unless your a Shonen type of anime.