This was posted over on CoFR by Draco (don't want to steal the credit, but these packs are nice. Try them.
Detailed textures:Summary:This pack was made by Soylient Green. There is no direct link talkin about this pack, but the links to other discussion is below. It is constantly updated, so get it every few weeks. Install it, and then type r_detailtextures 1 in console and, voila you are set! I'd recommend using the less bumps textures, but it's up to you!
Get them here: ClickehRead About Them here: ClickehAmbience PackSummary:Updated 4/22/04 - Replaces default ambience with higher-bitrate, hand-crafted sounds.
What's New in 4.0:
-Finally replaced old 8-bit Half-Life sounds in Hera and Nancy.
-Thoroughly re-edited with new reverb engine: Gverb!
-Properly inserted repeat flags for a few wavs that weren't repeating.
-Increased mp3 bitrate from 96 to 128 for higher fidelity.
Get them here: ClickehRead about them here: Clickeh