best way to customize the WP menu style?

I am trying to give my wordpress site a bit more individuality and i feel like the first thing is to change up the standard wordpress menu look.
Are there plugins/widgets to best do this or should i screw with the CSS?

Thanks all

[Duplicate, more or less: http://wordpress.org/support/topic/shorten-height-of-nav-menu?replies=2#post-3677914%5D