Tec: Breaking with the trend, I think people are playing with history-colored goggles here.
Unreal was really quite groundbreaking for it's time, and I think anyone that was there and played it will always remember the shock when they stepped out of the prison ship into the world. It was, for that time, great stuff.
However, retrospectively, Unreal II is the better game. Graphically it's (literally) years ahead, and in some places it's just downright brilliant. There are spots in U II (like the pseudo-geometric, music-sync'd opening sequence) that are far better than most intros today. Something that wasn't as obvious then, but is In Your Face(tm) when you fire it up with a modern graphics card. The story is actually quite good, and the generally dark graphics are beautiful if you play in a dark room and enjoy the truly alien environment.
Unfortunately, at the time U II was pushing the hardware envelope. I doubt many have played it through on max settings to really see what it had to offer. But having played all the Unreal titles through multiple times, I would call U II the best of the bunch. They're all good, but to go back and play original Unreal now is kind of... raw. Where U II is still immersive enough that you can really get into it.
All good fun, for sure. My only complaint for GOG is at $10, they're overpriced for something this old. Even UT 2K4, though maybe that's more justifiable given in many places 2K4 is more fun than UT III.
[Disclaimer: mine is the voice of obscenely bleeding edge hardware]
Agreed. As a fan of the original games, I still thought U II was a great game, despite all the (IMHO) unwarranted criticism.