Dunno if you can call those eps in Utena filler since the anime came out just before the manga.. plus they're very different entities anyhow. They were just lazy flashback episodes. And yes, they were quite good.
One of my faves is the ridiculous Ninja - Early Nazis - Superspecialawesome Blue Flowers arc in the Kenshin anime. I love it because the entire scenario is so damn out there that its hilarious. Kenshin fighting a dude on a horse with a jousting staff. I mean,.. come on.