a-S has higher image quality, but DBNL shows more. a-S uses source material with the original 4:3 640x480 resolution, while DBNL has the remastered 16:9 resolution (Dragon Ball used cells larger than what was originally shown, so there actually is image material to support 16:9, though the extra material was drawn as throw-away to begin with). I can't give a clear recommendation as it depends on what you value you more (image quality or extra image material).
I believe a-S is uncensored as well, but I haven't had time to search for an episode that proves it. If you find out, do tell me so I can add it to the thread for others.