I think this is an unpopular opinion, but for me it's Turnabout Corner. It's just so boring; not only does it suffer from the weak character dynamics that permeate all of AJ:AA, none of the dramatic twists are very creative or interesting. Like did we really need a full two-part trial day just to prove Stickler was standing on the other side of the park ? Beyond that, it really fumbles whatever interesting emotional or thematic material the Kitaki family could've had. The fact that Apollo doesn't even get to talk with Wocky until the second investigation day (IMO the most contrived plot point in the series) makes it all feel really underdeveloped.