I really like Project Reality, great weather/lighting mod. Sharpshooters is a good ENB that is not very demanding. If you don't know what an ENB is, basically it makes your game look better. Lush Grass, Lush Trees, Skyrim Flora Overhaul, and Skyrim HD are all good mods to make the environment look better but may hit your performance. Most people prefer Skyrim HD over the texture pack on steam, but its an opinion thing. If you ever get into gameplay type mods. Skyrim GEMS is a great place to find them.