Wasn't around for that one, but I've seen a few in my 32 years (sadly, never one in person though). The one most fresh in my mind is Halladay's perfect game earlier this year, and I thought his stuff was far better tonight.
I thought his changeup today was a lot better than the one he threw in his perfecto. Today’s changeup looked like it was whomping the big black cloak in front of it while shifting on its way to the plate. The Reds couldn’t hit it decently if they’d been swinging garage doors, it was that good.