Before I got my Galaxy Nexus, I was a die hard user of GO Launcher EX. I was actually reluctant to try it at first, but a good friend of mine basically forced me to use it for a day, after which, I never looked back (Thanks, Chris!). I can't imagine having a pre-ICS phone without installing GO.
Now, the GO Team has brought the goodness of GO Launcher EX to Android 3.0+ tablets by way of GO Launcher HD. It's still in beta at this point, though it doesn't quite have that "beta" feel to it; in fact, it already feels polished enough to use as a daily driver.