The thread is "BEST" anime attack ever. That could mean powerful or coolest. It's pretty much what your favorite attacks are.
"Vaporizing the solar system" is a rather ridiculous thing. DBZ is a very silly anime, and I would not call it cooler than Full Metal Alchemist.
I like the more grounded and down to earth anime, those that focus more on interesting plot rather than ridiculous attacks.
I find grounded action much more interesting and cool than an attack that can destroy the galaxy, but bounces off of a person's skin.
The ridiculous over the top stuff wears thin VERY easily for me.
Sure kamehameha is more powerful, but it's because the DBZ world has less rules and is quite silly and lacking in interesting plot a lot of the time.
I like powers with limitations because the characters have to think about situations according to the rules of their world. A bad ass is more bad ass when he can win despite limitations and mortality.
An invincible man that can blow up the galaxy has nothing to fear. When it gets to that insane level, it is just durab.
I HATED most of DBZ; Dragon Ball was such a well written classic. It had silly attacks, but it remained a silly modern day fairy tale and didn't try to act so epic and manly. They clearly had to up the power level to compensate for a lack of writing prowess and interesting ideas. Giving the world rules and boundaries presents a challenge to the character and the writer that make the story interesting. If anything goes, then any cop out can be accepted. How would Goku do if he had to be a smart fighter instead of a meat head?
It is just a matter of taste. I like the mature stories with believable characters and at least some what grounded action.
If that makes me durab, then so be it
PS: By the time a kamehameha is charged, the user could have been stabbed, beaten, or shot about seven times over.