This is my flicker photo set on convention badges I have collected over the years. I am missing a few of them, probably only about a dozen or so, but this means that I have been to over 100 cons since 1983 (Constellation in Baltimore was my very first, EveCon II was my first one where I had a badge).
If the average con is 3 days, this means I have spent close to a solid year of my life at cons. I have probably worked at over 90% of them, with the majority of non-working conventions being in my teen years, and the last con I attended and did not work at was... Brickfair in 2008. I think the number of cons I attended but did not work was less than 10 since 1990.