Ah,
Ultima IV: Quest of the Avatar. You've given me so many memories. I recently played a little bit of you on my ASUS Transformer using a Dos emulator. The news of various sites asked to take down a way to download you had your fans buzzing.
Now, the truth is here as EA and BioWare has opened
Ultima Forever, a site celebrating all things Ultima. And to kick off the site, you can grab a copy of Ultima IV for free. You'll need a Dos emulator to run it, but it's free for you to play. I can't believe it's been over 30 years since its release, but I'm glad that a new generation of folks can get to play it without having to pay.