I've used Fakefactory's Cinematic Mod since version 6 and love it. Due to it using more than 2GBs of RAM, its really designed for 64-bit operating systems, but using the /3GB switch in my boot.ini (I only use it for this mod, btw), I'v had no problems running it in 32-bit Windows XP (v6 and 7 had occasional crashes, but thats no big deal. CM8 hasn't crashed a single time yet
).
What it is is a mod that makes the textures and characters look much better, uses new music and sounds, etc. CM8 also adds in parts of HL2, Ep1, and Ep2 that were cut out, from what I understand (I haven't seen it yet, but I believe in v8, the final battle in Ep2 is a bit different). Do note that CM8 requires you to have The Orange Box (or at least Ep.2, I think), because it brings the Ep2 engine to HL2 and Ep1 (yup, HL2 now has full HDR like Ep2 did!). Its pretty sweet.
Also, FF is working on a 32-bit version, which should make things easier on the ones with 32-bit OSs that don't wanna mess with their boot.ini files.
--2Cold Scorpio, Rogues' Guild class 1A
Guildcom.us
"We'll build a perfect beast with the knowledge that they seek; if it takes 10,000 years, we never will retreat!" --
Prophecy, Iced Earth
