Jeez, it might be obvious, but what a ridiculously brilliant group of musicians they were. Seems almost perverse to think that without Warhol they'd probably have just put out a couple records on ESP-Disk and retreated into respected obscurity by 1970. Modern music without them is just inconceivable. Maybe there's a few clunkers on "Loaded" (and I'm disregarding "Squeeze" but then I've not heard it) but every record is completely different, and yet they've all left so much in their wake.
I still find absolutely everything they ever did completely breathtaking.