In 2004 I attended Cato University and had a blast (plus I picked up a bunch of free books). It was so much fun, in fact, that I didn't have time to blog much about it during the week I was there!
I was a little wary of attending at the time because I'm more of a conservative than a libertarian, but my between-ish positions were well-accepted and I had a lot of fun debating and arguing with all the other attendees and lecturers. If that sort of thing sounds fun to you, check out this year's offerings: