So in Skyrim if you enter a dungeon at an early level it will stay populated with enemies of that level that you entered at. Also if you get a unique item at a low level it will stay low level. Is there any way to reset dungeons/items to match your current level? This is really annoying as it forces me to do boring stuff until I'm high level and then do fun dungeons/get unique items.

Not sure if this will reset a cell to your level, but here's what I found on UESP:

Console Command: resetinterior

Function: Reset an Entire Cell

Description:

This command will reset an entire dungeon or location to default, including monsters, traps, chests and loot. E.g., ResetInterior Stillborncave01 or ResetInterior 00015206 would reset the dungeon Stillborn Cave to default; all monsters, traps, and loot would be respawned. If you reset a cell you have just been to, you'll need to use pcb command (purge cell buffer) as well, or the game will reload the buffered version of the cell, with all the modifications you've made to it. Both editorID and formID are acceptable in this command. Using this command in player homes appears to reset the furnishings without clearing the contents of initially empty containers, however, all weapon racks and cases will be empty and mannequins will need to have their inventories removed and replaced. (viz., the bedroom chest)[verification needed]

I don't think there's a practical way of resetting the level of the cell. The Reset function doesn't affect "Encounter Zones," which is the level setting that gets set when you first enter.

On the other hand, I don't quite see why you'd need to. For example, my current character didn't start the MQ until she was at level 40, and went through Bleak Falls Barrow at level 41. There was no real difference in the dungeon at that level, from the characters I've taken through at level 3 or 4, other than that the enemies who spawned were at higher level. The experience of the "fun" dungeon was essentially the same. And you will pick up level-appropriate loot at any of the "boring" dungeons (although I really don't know of any I'd call boring. )

i agree with glargg here OP. i understand and empathize with not liking the concept of not being able to get unique items at their highest level, but, you will more than make up for it by the loot you get and those dungeons are definitely fun. and, in truth, how did you even know their was a "best" level for that item?

my current paladin began the game in solitude (console) and so the items i've recently begun getting as i head towards whiterun and eastern skyrim are much better at my current high level than when i did the same exact dungeons with a low-level pc.

like glargg, i'll be doing the mq, BFB and all the other quests i normally did at lower levels at much higher levels with this pc and will have a blast and get better loot to boot.