I'm hopping this will be a sticky, anyway there's been a few posts here and there that talk about textures, but I just thought I'd post a link to all the textures you'll need for Unreal and Unreal Tournament.

http://www.oldunreal.com/textures.html

Downloads can be very slow, so it might be a good idea to pack them into a torrent or a file sharing site or something.

I was just wondering about the S3TC textures. I used to have original UT99 game that arrived on 2 discs CD1 was the game, CD2 was the S3TC texture pack which made the game look amazing back then on my S3 Savage3D card (only cards with S3TC support back then along with other S3 Savage cards). And i was wondering why GOG didn't include CD2 content into the game. I'd buy UT99 again if they'd do so (i still have the original + Anthology version and i'd buy GOG version yet again just because of the S3TC textures).

Or is the content that you linked the same S3TC textures from CD2 that i'm talking about?

The content he linked to you is way better then CD2. The CD2 has some issues which will cause the skating player bug on some servers but the newer S3TC textures by Diehard don't suffer this problem and are much higher resolution as well as covering a lot more textures in the base game then CD2 ever did.

CD2 also included old versions of ChaosUT and Rocket Arena which you can find elsewhere.

Thought I'd also note that if you plan on hosting a server in-game with friends the S3TC textures will prevent them from joining. Learned the hard way, and have stuck with stock textures ever since.

This isnt really a problem anymore, the CD2 textures have issues but the newer UTRP URP Textures have all been fixed so they don't cause the scating players glitch anymore

I was actually referring to texture mismatch errors using the S3TC textures here (granted, my friend was using the stock textures):

http://www.uttexture.com/UT/Website/Downloads/Textures/HighEnd/HighEnd.htm

Hmm dont know anything about that, I've never had a problem using those textures online or over lan before though, you didn't accidently use the UT textures on Unreal or vice versa?

Nope, they were definitely the UT textures, hi-res Earth on Face and all. The only modification I made which shouldn't have made any difference was including the "low-res" S3TC (not 2nd CD) textures for those that did not have a "high-res" equivalent.