I have a game that uses a total of 81 mods and I could use a few textures for some mods as my world just looks weird with default vanilla and faithful textures clashing with one another.
1: Fossils and Archeology Revival: This mod is in 1.7.10 now but is working toward a 1.8 release. The guys at the main thread at minecraftforum.net could appreciate a texture pack addon for this mod especially as it can help to spread the word of it's existence. Very few texture packs for this mod has been done, and even then packs have only four textures for a few blocks. There's quite a few things in this mod that need a re-texturing from the animals one can clone to the machines used to clone the animals as well as other mod-exclusive entities and ores/plants.
2: Enhanced Biomes: This is a pretty unheard of mod from what I noticed, it adds a bunch of new aspects to both environment and world-gen. It would be nice to have a texture pack addon for this mod especially.
3: Metalurgy 4: Metalurgy 4 needs representation within the main Metalurgy mod's texture pack, especially with the Extra TiC mod's tool parts craftable through the tinker's smelter.
Also speaking of tinkers construct might it be possible to make a new texture for the mossy look for tools with the Auto-Repair modifier? I get wanting to stick to the vanilla textures, but the vanilla texture for the mossy-covered tools makes them all look real ugly, and the faithful pack doesn't really make it better. The moss shouldn't be swarming all over the working end of the tool IMO, since it takes away from the beauty of the tool one created through tinker's construct. Might it be possible for an alternate texture for those who want a better-looking moss-covered item?