2. Anakin Skywalker
While to this point, there have been no direct hints of Anakin Skywalker appearing in the series, given Ahsoka’s backstory and relationship with Anakin, it would be a missed opportunity if she didn’t.
Although they never met in a live-action appearance, as a part of The Clone Wars series (which the character Ahsoka originated from), Anakin was her master and one of her closest friends. And as such, it makes perfect sense for him to appear in her story in some capacity.
At this point in the Star Wars timeline, Anakin Skywalker has been dead for several years, however, including him either in a flashback with a young Ahsoka or as a Force ghost is still well within the realm of possibility of doing, and could fit well into the story.
It may be a bit “fan-servicey” to have them meet in live-action, but that doesn’t necessarily make it a bad thing, especially if it fits well into the story.
Anakin could either come to her as a force ghost, once again trying to mentor Ahsoka after she has lost her way, or she could reflect on a memory of the two of them training together during her years as his apprentice.
With Hayden Christensen set to reprise his role as Anakin in the upcoming Obi-Wan Kenobi series and him clearly willing to return to the franchise, I see no reason why Disney and Lucasfilm couldn’t make it happen.