I was once designing a leaflet for my friends catering service which required me to use the plural of 'menu'.
Menus looked wrong, because I thought that it looked like some sort of Latin word, pronounced 'men - us'.
Menues seemed more logical, but the 'e' looked out of place.
Menu's looked right, but I knew that the apostrophe couldn't be justified.
After consulting the Concise Oxford Dictionary, Fowler's 'Modern English Usage', the Longman 'Guide to English Usage' and F.T.Wood's 'Current English Usage' (all of which are on my bookshelf), I still wasn't certain, so I phoned Ipswich Reference Library. A quarter of an hour later, after three librarians had consulted several different sources, and had debated the issue among themselves, we agreed that it should be menus.
It was only then that I remembered that my friend, who I was designing the leaflets for, is dyslexic - so she probably wouldn't notice my spelling anyway! ;-)
Chris