I took the top 1500 sites from Alexa.com and checked their registrar. Some companies have already said they were moving (Hi StackOverflow!). Huge thanks goes to Mike St John for his help in querying the registry.
Here are the 144 companies using Godaddy as a Registrar :
woothemes.com
proboards.com
stackoverflow.com
alot.com
wowhead.com
xkcd.com
seriesyonkis.com
exoclick.com
flipkart.com
goodreads.com
twitpic.com
babylon.com
bytes.com
opera.com
foursquare.com
r7.com
thechive.com
realclearpolitics.com
yousendit.com
dreamstime.com
justdial.com
ilivid.com
github.com
multiply.com
imesh.com
optmd.com
wimp.com
youm7.com
urbandictionary.com
amung.us
informer.com
pingomatic.com
networkedblogs.com
histats.com
chicagotribune.com
grooveshark.com
infusionsoft.com
buzzfeed.com
trulia.com
yoo7.com
hawaaworld.com
bearshare.com
slutload.com
piriform.com
incredimail.com
noticias24.com
ioffer.com
buysellads.com
isohunt.com
4shared.com
kaskus.us
adcash.com
imagebam.com
imageshack.us
imageshack.us
imgur.com
modelmayhem.com
wikia.com
instructables.com
youjizz.com
4tube.com
hootsuite.com
facemoods.com
cafemom.com
elegantthemes.com
bestvideodownloader.com
egotastic.com
break.com
plusnetwork.com
pof.com
chatvibes.com
amung.us
makeuseof.com
ted.com
mediafire.com
fatwallet.com
imageshack.us
bitly.com
inbox.com
perezhilton.com
skype.com
metrolyrics.com
templatemonster.com
meituan.com
zillow.com
mgid.com
latimes.com
addthis.com
infolinks.com
mashable.com
stackexchange.com
liveleak.com
majesticseo.com
swtor.com
softlayer.com
digg.com
xtendmedia.com
sweetim.com
178.com
businessinsider.com
magentocommerce.com
quickmeme.com
dealextreme.com
docstoc.com
sparkstudios.com
backpage.com
snapdeal.com
empowernetwork.com
linkwithin.com
fiverr.com
wordreference.com
filehippo.com
mangafox.com
kaskus.us
fishki.net
scribd.com
klout.com
compete.com
tuan800.com
1stwebdesigner.com
foxtab.com
lashou.com
kaskus.us
ringtonepartner.com
porntube.com
sendspace.com
amung.us
yfrog.com
adjuggler.net
blackhatteam.com
fanfiction.net
seobook.com
celebuzz.com
basecamphq.com
brothersoft.com
linkbucks.com
vk.com
soundcloud.com
miniclip.com
examiner.com
searchqu.com
thepostgame.com
fatakat.com
articlesbase.com
zap2it.com