I'm the sort of guy that would like a lot of immersion in my RPGs, and whenever I finally get my hands on Skyrim and start playing, would you recommend first playthrough with mods that increase immersion or vanilla.
I have a highly dedicated friend (who bought it day1 and already played 500+ hours) who insist I play it vanilla first because he feels that i should enjoy the artistic vision of bethesda's developers first without anything to stain it. Also points out that it would be best that I avoid mods in case it breaks the game. So he only recommend debugging mods.
I dont know too much about Skyrim gameplay but I've also seen a few mechanics, just like other Bestheda RPG's that break immersion (like having the carrying weight to hold a dozen swords or guns, stack up on gold or caps really quick, and never need to sleep or eat) and I've seen mods that adds immersion mechanics and makes the game a bit more challenging (which I would like)
Since this friend is a skyrim veteran and advise out of experience ( as well as personal preference and loyalty to TES), I am here to seek council on this matter before doing anything that would potentially ruin the experience.