Which is better to get The Steam version or retail disc version of skyrim? does it matter?

retail is the Steam version

Well, they are both the same. Steam automatically gives you the steam workshop and automatically gives you updates, so there is that advantage, but I thought the map you get with retail is nice. I have that hanging above my bed as we speak.

I automatically got the steam workshop (and updates) with my retail version, but maybe that's because I had to create a new account with steam (since I didn't have it before)?

The steam download was on sale last week for $39.99

I got it off Steam, thought I would prefer a physical version

Same thing. You buy it retail it installs on Steam.