Well I thin without a doubt, and it is not because it is free, Alien palette is the most versatile of all plug ins, it never crashes AI.
Alien Palette? Never heard of it. Went to go dig up info about it, and . . .
"Alien Palette is a plugin filter for Adobe Illustrator that serves no practical purpose whatsoever.
Alien Palette palette displays a picture, allegedly a photograph of an alien captured in a UFO crash at Roswell, New Mexico.
Alien Palette can be docked with other palettes. Great company when working on all-nighters. This version is not animated, so if you see it move you need to take a break. Soon."
VectorScribe, definitely. I wish AI could do this stuff on its own though.