The reason the Epic's screen looks pixelated is because the pixels aren't all square. The screen uses a PenTile configuration (Google it to see some of the funky pixel patterns). Some people notice it; some people can't. I for one hated it, enough to decide that I would never get a device with PenTile matrices.
Proponents of PenTile claim it offers superior clarity and color for images. I'm inclined to agree with that. However, I'm looking at text way more than images/videos/movies on my phone. Day to day, it's all about text. And usually small text. That's where the PenTile really sucks. None of the pixel elements line up in a straight line vertically or horizontally, which means a normally crisp line is now blurry due to anti-aliasing.
As far as color, the Epic's screen does deeper blacks, scoring it a higher contrast ratio. It is also a bit more readable in direct sunlight than the Evo. I find the colors to be unnaturally saturated. That bothers me, but some people love that.
I'm actually a big fan of Samsung LCD products. Ever since flat panel monitors have been out, I've owned a Samsung. My HDTV is a Samsung as well. And yet, I hated the Epic's screen, mainly because of the PenTile matrix.
-edit-
Samsung clearly took a beating with PenTile, and for the upcoming Galaxy S2 (a phone that looks pretty damn sweet), they're sticking with SAMOLED but ditching the PenTile.
http://www.mobiletechworld.com/2011...specifications-and-hands-on-video/#more-19567