Ok, so I’m gonna suggest you read some of this thread between me and @Desslock then
and also my full critique which, for reasons, wound up in the thread about X-wing.
Qt3 Games Podcast: Craig Miller and X-Wing Miniatures - #18 by CraigM
I give in depth analysis of what I think of the shows. And understand that I come at this from a joking, but only slightly, ‘the prequels? What prequels’ camp. It is the story of Anakin, but actually done well. He is a hero, conflicted at times, but hero still. None of the insufferable emo Annie of the dreadful Revenge of the Sith. So I can, whole heartedly, recommend watching both shows.
And my conclusion that you should watch at least one season of Clone Wars before watching Rebels? Yeah, definitely stand by that.
As for frequency? Anakin and Obi-Wan are the most common, but by far not in every episode. Maybe 2/3. It is an ensemble cast that may go off for a few episodes focusing on either a squad of clones, a crew of bounty hunters, Ahsoka on her own, the trials and training of young Jedi, even the politics of war where it is (usually Padme or Bail Organa) trying to negotiate, sometimes in secret, with various planets, or even the Separatists directly. So fear not, you won’t have to suffer through a stiff and unbelievable series of brooding ‘romantic’ dialogue with Anakin and Padme.