When I think of which stables were the best of all-time, I think of which stables made each member important. The n.W.o. never focused on all it's members. Shit, it got so overloaded with mid-carders and no-names, half of the time they didn't even all get television time.
Evolution is a great example of each member being important, but in the end, it was a rip-off of the Horsemen. Evolution was formed to help boost Triple H., and when any other member in the group got big enough and "important", ironically they were kicked out of the group. So that doesn't make the stable itself, great.
My pick is The Radicals! Chris Benoit, Dean Malenko, Perry Saturn & Eddie Guerrero.
No one individual was bigger than the other upon entering the company. Benoit got the most push out of them, but upon entering, it was actually Dean Malenko & Eddie Guerrero getting titles. Guerrero won the European title, while Malenko won the Light Heavyweight title.
Benoit went on to win the Intercontinental Championship, and Saturn ended up later down the line with the European title, but as a whole.. they were a great 4-some.
They worked well together, and often had each other's back. No one individual felt bigger than their partner.