I would take a look at the jQuery accordion menu by Marco van Hylckama Vlieg, simple, light and very customizable with styling. It has all the basic options for accordion, collapse, non-collapse, full expandable, etc. If you want something more complex or with more levels, you may not be after an accordion menu.
Don't forget when looking at demos that styling/images (all css) can make a huge impact on what you're looking at. With no jQuery changes, you can make a plugin look very much "your own" and fit whatever site you're putting it into.