Saw two great classics in the theater recently. First was Casablanca with the New Jersey Symphony Orchestra performing the score live. That was a fantastic experience, but was entirely dwarfed by 2001: A Space Odyssey in 70mm! I feel blessed by the gods to say that I saw a pristine 70mm print of 2001: ASO on the big screen, front and center about 10 rows back, with the screen nearly filling my vision, and the sound so beautifully loud that the high-pitched whine during the Stargate sequence was actually hurting people's ears (like it should). The overture, Ligeti's Atmospheres, played to a completely blackened house, and you could hear a pin drop from the moment it began to the moment the film ended.
Definitely a Top 3 Movie Experience for me. I feel like I can die a little more peacefully now that I've seen 2001 in 70mm.