It's debatable. IMO, though Jiggs recovery isn't interesting or anything like that, its a combination of air speed, six jumps, and good aerials that makes her recovery good. Unlike other characters who have multiple jumps, all of Jiggs jumps go full speed and height, so she can weave in and out, air dodge almost as much as she wants, and even if she gets hit, she can make it back usually. Though gimmicky up bs like G&W and Pika are better overall.
TMNTSSB4
I'm pretty sure Sheik's up-b is only vincible for one frame. If you mess up, it can kill you, and the windbox when she reappears makes her so hard to punish. I mean, Sheik's up b is relatively safe on stage, let alone off. The thing is, you probably won't be in any position to punish her up b at startup because she will have knocked you away or forced an air dodge with the ridiculous range and disjoint on one of her aerials like fair. Also wall jump and bouncing fish help a lot. She can pretty much recover from almost anywhere at any angle.
What sets apart many of the best recoveries is their nonlinear-ness. Their are exceptions, like Zelda and G&W, but you aren't going to intercept any of those within reason and the risk is too great. Pikachu, MK, Sheik, ZSS can do pretty much whatever they want off stage and recover anyway they want. They are very nearly ungimpable.
Ryu's recovery is linear for sure, but invincibility and the risk of edge guarding may make his recovery top 10-15. For now though, it isn't the same level of Pikachu/MK/Sheik/Greninja/etc.