Siege of Mandalore is my favorite arc

Of these, my personal ranking, from best to worst...

1. Siege of Mandalore

2. Battle of Umbara

3. Darth Maul's return and Mandalore takeover

4. Fives discovers Order 66

5. Fugitive Ahsoka

6. Asajj Ventress's new life

I'll start with Ventress, which I have little-to-no knowledge about this storyline. If I did, maybe there's a chance I would rank this higher. Presuming of course it doesn't get ruined by the character's recent appearance in TBB S3.

Fives discovering Order 66 is a pivotal story arc in TCW. One I did initially rank below Fugitive Ahsoka until I figured the insight of Order 66, and the effort to either discover or discard the knowledge, was more interesting. Whereas Ahsoka's was more or less predictable once the seeds where it was hinted that Barris Offee was the traitor became more or less known...at least, it was obvious to me. Which is a shame because this is technically our first exposure to the Jedi Temple guard, whomever he may be, who eventually becomes the Grand Inquisitor.

Darth Maul's return and Mandalore takeover story arc is indeed one of the best, simply because of the return of a beloved Sith Lord. Although if we're counting Darth Sidious's duel on Mandalore, I may rank this above Umbara. Otherwise, I gotta give Umbara some props for being one of the key story arcs which showcases the clones as more individuals rather than a number, and not every Jedi General has the clones' interests at heart.

Siege of Mandalore...need I say more? One of the last battles of TCW, and probably the most exciting bits to come out of the seventh/final season. Shoutout to Ray Park for reprising his role for animation purposes - which makes this even better.

Battle of Umbara by far. It was the one time the 2008 show approached the quality of classic Clone Wars tales like The Battle of Jabiim and Shatterpoint.

Darth Maul's return was adequate, if nothing special, while the Fives arc was a competent thriller dragged down by a nonsensical retcon.

The Fugitive arc is something I truly despise for its rampant character assassination. I find it emblematic of Filoni's handling of Tano. It's not enough that she be good, he has to tear down everyone else to make her look better.

The other two are from the revival season so I haven't seen them, but I doubt I'd care for them much.

Siege of Mandalore: I never cared for the Mandalorians much, and 2008!Mandalorians are even more boring, likewise I never cared about Maul much, and 2008!Maul is even more boring, and it has Filoni writing Tano.

Ventress' new life: It'll be starring 2008!Ventress. If the Fugitive arc is my most hated thing Filoni's ever done, his handling of Ventress is number two. In the comics and novels, Ventress was one of the most interesting, complex and dynamic characters in the franchise, and Filoni sucked all the life out of her to make her a fourth-rate Catwoman expy.

Mortis arc is my favorite

Indeed, Mortis is also another good one.

Mortis Arc humanized Ahsoka a lot

Some of these story arcs deserve to be movies tbh