Wedding Reception

Round or Rectangle....

I know this may seem like a stupid thing to be worrying about... But I'm not sure if I want to have round or rectangular tables! I've seen either done, but I'm not sure which I prefer!! My mom things circle is more formal looking and it is easier for people to talk. I agree with that.. but then I can't do table runners the way I would like. Help and opinions please! What is everyone else's preference??