SY - 10 (Oklahoma and Texas shows, NYC once)
Chelsea Light - 2 (Dallas and Denton)
LR and Dust - 1 (Lawrence)

*edited to include locations. I am kinda interested to see where in the world people have seen them too, if some don't mind including.

I saw Sonic Youth twice: July 2003 in Ilosaarirock, Joensuu (Finland) and October 2009 in Columbiahalle, Berlin.

Chelsea Light Moving once
Kim Gordon with Ikue Mori once
Lee Ranaldo & The Dust once
Lee Ranaldo with Raul Refree + some other guys, once

15 times from 1990 -2011... was at the Aaragon ballroom show when there was a riot afterwards, Red Rocks, First Ave in Mpls and several points in between.
Thurston twice
Kim once

Once, London for one of the DN shows, so 2006/7?

Saw a Moore/Nace/Corsano trio a year or so later in Brighton at a festival.

Very jealous. I would have loooooooooved to have seen them at Red Rocks...

Just once duriong the ertalan tour

Sonic Youth, 4 total. Then Thurston twice, Kim once, Lee once.