I enjoyed a completely unmodded Skyrim (on PS3) for several hundreds of hours, and now I enjoy a modded Skyrim on PC.
The one thing I really, really missed before was the bugfuxes the unofficial patches provides. Then some other mods fix other little things that has bothered me, like timescale, better interaction with followers, fewer generic greetings, fewer forced quests and so on, and I'll probably never take those mods away, but I managed without them.