I've been to three cons - or more accurately, one con (Fanime) each of three different years. Each time, it's been close enough to my home that I don't need to rent a hotel room, so that was great.
The first time was back in 2002 or so, when I bought a weekend pass and went primarily to attend the various 'classes' or forums they had on various anime subjects.
The two recent times were this year and last year, when I had a camera and went primarily to take pictures of people cosplaying as characters I recognized. I can post the link to my Flickr account, where I've uploaded all those pictures, if anyone's interested.