I like my fries plain.. unless of course they are from nathans.. then I'll make them chili cheese fries, and then it becomes a meal.. (I'd be full from the fries alone..)
I am not a big lover of ketchup but on my fries I like salt and vinegar or mayonaise. I think this comes from growing up in Europe. The salt & vinegar is from living in England and the mayonaise is from living in Germany.