I came to slam through women and poets doing spoken word who maybe were slam & maybe weren't, so I think there are tiers to this question.Personal, general, and then internal-community.
Personally,non-hierarchical order
Kimberly Simms- I am not sure who came first Cheryl B. or KJ, but they knew each other,suggested I get involved & recommended slam poets to book as features.Like Daphne Gottlieb.

KJ put a clock in my hand.
Lucy Anderton- because she looked at me and said "you, you're going to help me with this bout"
Alix Olson-She gave me & our scene a leg up.
Theresa Davis-because we've been at each other's sides now for almost the whole time I've been a poetry organizer.
Generally, I think name recognition is a big thing.
Saul Williams, duh
Patricia Smith Buddy Wakefield--tours with Sage Frances & the Ani tour brought some people around to our scene.
Taylor Mali the teacher factor can never be under estimated
Alix Olson and/or Staceyann Chin, if people aren't referring to one, it's to the other, in terms of festivals, indie bookstores, etc.
*
And for Canadians, Buck 65, dude!Internally, I think it's
Marc Smith, as the creator, as poet, as curmudgeon.
Patricia Smith because she's broken our own standards and records and broken that whole page stage thing.
RAC, her brass knuckle stamps on this list.I think her name comes up in team rehearsals more than any other.
Tony Brown, because he's prolific and calls sh* out like he sees it.He knows what's good and he still reaches for it himself.He's one of our higher consciousnesses.
Andrea Gibson & Buddy together, I think, turned a kind of climate---the way they present politics with hope,vulnerability, universality, and crunching images spun away from the politics as personal approach to so much poetry and made it the other way around, less rant, more everyday life connecting to the big.
:-)