I want to give Gintama a shot...but that's a hell of a lot of backlog. Like, not even like One Piece or Bleach where you can speed through parts, because it's a comedy series full of reference jokes where you have to be paying attention.

Stupid question, but should I start with the massive anime or the massive manga?

Also, apparently the anime splintered into Gintama-san and Gintama'. Could someone explain that to me?