Visio was much better back before they got bought out by MSFT.
Microsoft did cram in a lot of needless, confusing junk as is their way. But the database and web site diagramming are pretty cool. I don't mean make one yourself, but point it to a database or web site and it'll diagram the whole thing for you automatically. It helps when you're given a database or web site and are told "Re-do this."