I've probably been to a dozen. The best tech conference I've been to was FutureRuby. Single track, two days, great content, well-planned parties. Those guys know how to throw a conference. Too bad it was a two-time event (more of less).
Beyond that, I'd take the annual local Bar Camp over most national/international conferences. A strong local tech community is really important.
Beyond that, I'd take the annual local Bar Camp over most national/international conferences. A strong local tech community is really important.