Lately everyone seems to want animations on their websites.
Usually I pick the one that needs the fewest changes to make it work exactly like my client wants, but what I don't look at is the performance and the size of the framework.

Which JavaScript framework do YOU prefer above all and why exactly?
  • Prototype
  • jQuery
  • MooTools
  • ...
I'm only familiar with the ones above, so feel free to complete the list.