I like gripping first lines, and paragraphs.
I like a good story even better. I believe the best story I have written thus far starts with
He reached the hotel phone by the third ring.
I could have started it with a flaming baby or existential crisis, but that isn't where the STORY started. It started here. Over the next several paragraphs (it was a short story) there's stuff about marital problems, infidelity, mutual resentment, and it (hopefully) builds from there, but the best opening line is the right opening line....sometimes it's flashy as fuck, sometimes it is not. Here's the next couple paragraphs:
He reached the hotel phone by the third ring. He would have ignored it completely, but his cell had gone off a few minutes before, vibrating across the nightstand. He was Chair of his department, and sometimes important people needed to reach him.
"You're killing me, Tom. You know that."
Not someone important, just his wife.
"Is she in there with you, Tom? What does this one look like? Some bleach-blonde Barbie, with perky tits and an airhead giggle?"
"Amy, you're drunk." It was a deliberate slap, and for a moment she hesitated, but only a moment.
"You're deflecting, Tom. But that's what you do, lie and deny, deflect and object, until I just give up."
"There's nobody here, I'm alone. It's late," Tom said.
He smiled at the girl sitting on the bed beside him as he spoke. He could still taste the barest hint of her lips on his own, sweet and floral. Youth.
Eyes lit with mischief, the girl smiled back, sticking her tongue out. They'd met after his conference let out, in one of the bars at the Universal Studios theme park. One of the perks of research was the conferences; dozens each year, all over the world. Vegas, Orlando, San Diego, he'd even been to one in Cannes. He tried for at least four each year, and usually found a girl or three in the time he was away.