I know there are others out there as fanatical about fries as I am, so I'm here to add Hayes Street Grill to the list of great french fry makers in SF. Perfectly crispy on the outside, hot and soft inside. There wasn't a soggy fry in the bunch, and they were served burn-your-fingers hot. So good, I didn't even ask for ketchup (or mayo)
Other memorable fries:
-skinny fries at Plouf or Jeanty @ Jack's
-fast food fries at The Great Steak Escape inside the SF Shopping Center (but only if they fry them after you order). The mayo is exceptionally good here, though maybe it's just my imagination.
There must be others...
I love them all: skinny fries, stick-like fries, krinkle cut fries, steak fries, garlic fries, salty fries, the list goes on and on. I'll devour them all.
What other restaurants have great fries?