[gabriel666smith]

I was taught to use the term "action sentence" for an opening line that actually does something to a reader, and to aspire to that. I think it's a Gordon Lish-coined term, but it might not be.

Hard to pick an absolute favourite, but one would be:

"There was a time when I thought a great deal about the axolotls."

From Cortazar's short story Axolotl.

I don't know for certain why I find it so evocative, but it certainly draws me in, and makes me want to know more.

Quoting without looking attempt:

"I went to see them in the aquarium in the Jardin des Plantes and stayed for hours watching them, observing their immobility, their faint movements. Now, I am an axolotl."