I prefer http://www.nexusmods.com/fallout3/mods/16935/? over Realistci Lighting Overhaul. The latter has more contrast and almost pitchblack darkness in parts, the former is not as black and has less contras.
NMC is great and it's my base replacers. I like http://www.nexusmods.com/fallout3/mods/19799/? and http://www.nexusmods.com/newvegas/mods/42028/? as well, so install those over NMC. Poco Bueno is for FNV but the games share a lot of textures, so works with F3 as well. http://www.nexusmods.com/fallout3/mods/8498/? pack is mostly excellent.
For armor/clothes I use http://www.nexusmods.com/newvegas/mods/54478/?as the base. It's for FNB, but same there - lots of textures are the same in the games.
For weapons, the newly released http://www.nexusmods.com/fallout3/mods/21245/? is excellent.
And then there are lots of more particular replacers that are excellent as well.