This mod replaces all character textures (that includes characters from any faction, even the generic units), with textures normally only seen in cutscenes which are 4 times larger. The difference isn't as large as you'd think as the game's artstyle always end up adding some blur, but it's still noticable, especially at higher rendering resolutions.

Here's a couple of comparisons. Left is normal, and right is with high res textures. Make sure to click to get the full picture.

You can download the mod here: https://www.fluffyquack.com/VC/mods/HighResCharacterTextures.rar

Install instructions are in the readme.txt