Hello There.

I´ve tried:
1. Prototype with Scriptaculous
2. JQuery
3. Mootools

Some how i seem to prefer Prototype and JQuery at the moment perhaps because i´ve used them the moast.

And i like the easy way you can make effects the easy way with Prototype together with Scriptaculous.

Good luck!

__________________
Of course the whole point of a doomsday machine, would have been lost if you keep it a secret.