I think my consistently favourite styles are:
jive (if I can't have lindyhop)
paso
charleston
I think that's because most people can make them entertaining, even the not-so-good dancers. I love the classic ballroom styles, especially viennese waltz and foxtrot, but only when they're done well - I get bored when they're not. And I also love a good salsa, but again, it has to be done well for me to enjoy it.