Wikipedia was the big one, and it was the only one I found that was inaccessable. Craigslist, google, wired.com all had some sort of blackout or redacted words, but you could choose to see it normally.
This is a day too late for you Austin, but you could have used Wikipedia from your smartphone like normal, the mobile site was working fine.
Here's a good list:
SOPA blackout: Who