I caught an episode of ThunderCats Classic on Teletoon tonight, and it was the best ThunderCats thing I've seen in weeks.
Episode 58: The Mountain
Out of sheer boredom Lion-O climbs a mountain. The mutants decide to attack putting themselves and the ThunderCats in danger.
The plot was superbasic, but it made great use of a limited cast -- Lion-O and Jackalman primarily, with Panthro, Tygra, Slythe, and Monkian as backup -- and it was fucking entertaining.
It makes me want to revisit the old series in its entirety, but I know there's a lot of shit lurking in there.