Looks like the larger arcs not yet covered are:
- Corruption/Academy on Mandalore, plus the other Death Watch episode (potentially good setup for Maul’s later takeover and the Mandalorian scenes in Rebels)
- Citadel Arc (definitely a vote here, the Tarkin story is fun, though this could probably be cut down to a lot less volume)
- Umbara arc (fan favourite but a bit bloated)
- Kadavo arc (not bad but not awful - least important of all of these I reckon)
- Onderon arc (Saw Gererra’s first appearance and early rebellion sparks)
- Clovis arc (fun scenes but mostly dull politics)
I think that’s everything not already covered by your series.
From (poor) memory:
Corruption was I think just Ahsoka
Citadel was Anakin and Obi-Wan
Umbara was clones, then Anakin later(?)
Kadavo was Anakin and Obi-Wan
Onderon was Anakin, Obi-Wan(?) and Ahsoka
Clovis was just Padme
I think you get most bang for your buck in terms of continuity with the whole saga with Citadel/Umbara(no Anakin) > Umbara (Anakin) > Onderon, peppered with as much decent Mando stuff as you can get in there. But that’s without taking into account quality, length of time, transitions, etc etc.
If it were just me, though this is probably unpopular opinion, I’d be happy to just have a ‘misc’/anthology episode for the sake of keeping as much content as possible rather than worry too much about structure.