I'm sure this has been asked before, but I couldn't find anything using the search option.

As the title says, there are unique leveled item in the game, listed here (slight spoiler):

The list isn't as bad as it was in Oblivion, especially since I don't care much about robes.
But the question is, what is the minimum level I need to be in order to get the best version of these items?

Please, let's not turn this into a discussion about the pros and cons of Skyrim's leveling system.

In Oblivion, it was 35, i'm assuming the same or close in this one and currently levelling without doing any missions.

I thought Oblivion had some leveled items up to level 40? We won't really know for sure though until we get the Construction Set.

At any rate it's probably mid to late 30's at least. I got the 50 magicka Mage's Circlet at like level 25.