For a top quality render, you need both. Personally, I would put lighting ever so slightly higher. A good lighting setup can make a mediocre texture look good, but a bad lighting setup can make a brilliant texture look awful. But similarly, you can have the best, most realistic lighting in the world, but if the textures you're using are low-res, blurry, or have false shadows and highlights baked into them, they'll drag you're result down.