Feel free to point towards everything I forgot.
I don't like resource packs, but some people do, so here you go.
These packs might not 100% up to date, but they are only missing a few textures.
Faithful Modded Edition (Missing GUIs though)(Good GregTech 5, Advanced Power Management, GraviSuite, CompactSolars and Advanced Solar Panels support, very partial Nuclear Control support)
Weed Warning Pack
Weed Warning Pack (Doge Edition)
Soartex Modded (Warning: extremely beefy computer required)(Good GregTech 5, Advanced Machines [Atomic] and Advanced Solar Panels support, partial CompactSolars support)
Zederrian Technology (Strong GregTech 5/6 support, very partial GraviSuite and Advanced Solar Panels support)
Pyrolusite's IC2 Alternate Textures
Minimalist Technology (Previously known as Pyrolusite's GregTech Alternate Textures) (Strong GregTech 5/6 support)
IC2 for Fable of Glory
IC2 Modern Resource Pack
Unity (Strong CompactSolars, Advanced Machines [both] and Electro-Magic Tools support)
GregTech Faithful Fanver (Good GregTech 4/5 support)
PureBDCraft: Advanced Solar Panels (Strong Advanced Solar Panels support [duh])
PureBDCraft: Nuclear Control (Strong Nuclear Control 1/2 support)