Can you believe Cell? He has the DNA of Vegeta, Freeza and Yamcha, so he could be prone to overestimating himself. Although he did surprisingly say that he's nearly as strong as Gohan when he came back, rather than claiming to outright be stronger. But really he had nothing to base his comment about A16's bomb on. He has no way of knowing how strong the bomb was. Him showing fear could be an indication that he thought it could kill him, but honestly it might just be he was scared of being hurt badly enough for it to ruin the fun he was having toying with Gohan and the others and thought the damage could be enough to lead to his eventual defeat if everyone ganged up on him later (yeh he was seemed like he was just having fun with the Games, but he clearly was angry about losing too, once Gohan went SSJ2). But still, he really had no way of knowing. He's just making stuff up.
Vegeta's is probably the strongest one, just by virtue of being the most powerful fighter. Unless there's some reason that him having to worry about destroying the Earth would make his blast weaker (like he has to spend effort controlling the direction of his ki so it doesn't leave the area). I guess it depends on how Vegeta and Cell's self-destructs actually work. Is it just them pushing the intensity of their aura to its maximum/depleting their ki reserves as fast as possible while also expanding it out a bit? Then it might actually be more powerful in Vegeta's case, since the volume he's covering with the same amount of energy is smaller. Plus it's probably not as difficult a technique as if it was a final flash type ki attack but made to fire in an orbit rather than in a line. But Cell's self-ds doesn't really seem like it was just his aura, because then why would he need to get fat? So probably he another mechanism, but I have no idea what it could be.
Chaioutzu kamikaze attack
too powerful for Nicktoons.
Legit the saddest one for me.
