Well this is strictly during exploring or battling, I wear Blades armor, Thieves guild Armor, or Apprentice Robe... with Shrouded Cowl, or Apprentice Hood... Nightingale boots, with enchanted gloves and jewelry.

Currently my battlemage dons Daedric Armor. When out and about in town or going for a walk, she wears Tavern clothes and that pair of clothing that looks identical to chef's tunic but with different colors.

I recently started a mage and he's wearing expert robes of restoration, boots and gloves and will soon have mehrunes dagger.
He's weilding a cheapskate vorpal at the moment:)

The Blackest of Blacksmith aprons while I'm in town, I wear Enchanted psiijic robes (Via CC) when I cast, and I wear a scary set of steel plate when I'm feelin' angry.

Whiterun guard uniform an dwarven everything else including greatsword.

With my Breton, Elven light armor, heavily enchanted, that I've smithed the dikeens out of.
My Bosmer's in Linwe's Armor.
And my Altmer, those fur lined boots Jarls wear, some gloves, & the Archmage robes.

Daedric armour
Daedric boots
Daedric gloves
Guildmaster's Hood

It cuts an imposing figure, especially from the back of Shadowmere.

I prefer the iron and banded iron armor's "look," especially the banded iron shield, but I usually end up in Wolf or Blade armor.

Legendary Doom Guard armor heavily enchanted-
Armor- heavy armor skill +25, health regen 31% faster
Helm- bows +40%, conjuration 25% less
Gauntlets- +62 magic, +25 heavy armor
Boots- muffle, +40% sneak

Gift of Sithis(necklace) sneak +40, fire resist +46

Mistress of Sithis(ring) sneak +40, fire resist +46

All the fire resist is because she has been stage 4 vampire for almost an ingame year. With the sneak bonuses she can dissappear in broad daylight while at stage 4 in the middle of towns.

While in town its jester boots, enchanted tavern dress with health and magic regen, gloves with sneak and distruction, and the halo of Sithis with archery and waterbreathing

My Breton Mage character wears dragonscale armor with a mage's hood, all enchanted and smithed to god status. By level 46, I realized how bored I was playing a character that has no worthy opposition, so I started a new game as an Orc warrior with limitations.

My Orc warrior character only ever wore Iron, Steel, and Blade armor, all decently smithed (not god-like) and no enchantments. He's at level 47 at the moment.

Recently I've been playing a new Bosmer character that specializes in only archery, one-handed (daggers only), sneak, light armor, and alchemy. Right now she's a level 22. For most of the earlier levels she was wearing fur armor with a forsworn headdress, which looked pretty sweet. She also has a full set of Elven armor, which she wears occasionally. She's supposed to be a huntress and a mercenary, and joined the Dark Brotherhood today, so now she's using shrouded armor with an elven bow/arrows, and a steel dagger which is soon to be replaced by Mehrune's Razor. When she's in cities or towns, I always switch her to normal clothing. I always keep a few sets that I like in her inventory. As a straight male, I never thought I would ever have an opinion on which dress looks prettier, haha.

Copper and Ruby Circlet
Master Robes of Destruction
Gloves
Gold Ring
Gold Necklace or sometimes Amulet of Talos
Fine Boots (Short)

I wear Robes.

Mhairi gets about in iron armour, Imperial light boots, leather bracers, with a baskethilt sword (Jaysus) and banded iron shield. She also has a grey burlap cloak (Cloaks of Skyrim) and a novice mage hood for crappy weather.

It depends on what region I'm in. When i'm in the North I typically wear fur based armor with as much covering as I can manage. Toward the middle I wear light armor like leather, but also heavy armor if its full plate. In the South its pretty much whatever I want which is typically heavy armor.

arch mage robes
enchanted boots resist fire and shock
enchanted criclet of destruction
enchanted mythic dawn gloves of increase magica
savos arens emulate
ring of destruction

When I'm playing heavy I tend to use steel, then Dwarven until I can get smithing higher, then heavily smithed Steel. Occasionally I use Daedric for the look. For light I go to leather, then to either: a) a custom leather armour I made using the TG models, or b ) glass.

Robes, and Hood. I have an irrational hatred of armor.

My highest level character, a Nord, is in a suit of Daedric armour. I have an Imperial in full Dwarven armour but will upgrade as time allows. My sneak-thief Khajiit is in a mix of Nightingale and Dark Brotherhood armour, and my newest character, a Dunmer arcane bladesman, is in some black robes currently.

But hey - Is there a reason other than smith level limitation/time spent playing/looks/enchantments that some of you opt to wear things like steel plate or leather etc rather than the armour with the highest possible defense rating?

None.

I found a new look i like for my buff barbarian when feeling murderous....execution hood, ragged trousers, gloves, boots and the headsmans axe

Master Robes of Destruction
Mythic Dawm Gloves
The Boots that Savos Aren wore
Gold Ring
Gold and Ruby Necklace
Gold and Ruby Circlet
(everything heavily enchanted)

Wearing http://skyrim.nexusmods.com/downloads/file.php?id=17779 now... so awesome.

Full enchanted, legendary Dragonplate armour and shield. Will be making a Dragonscale set once I have the parts. Used to always wear Volsung with my old armour sets.

Head: Krosis (20% in archery, alchemy, and sneak, I think. I only care about the archery)
Arms: Nighingale (for the boost in armor rating, don't care about the enchantment)
Feet: Elvish (60% against fire)
Torso: Nightingale (60% against frost)
Neck: An amulet that boosts +50 to magicka, health, and stamina
Finger: archery 30%

I've not found anything better than what I'm wearing, though I've seen better armor in the rating. However, the trade-off to fire/frost protection outweighs the +10 in the armor rating.

Dragons and all that.

I also carry a couple of other items I can swap out, if the need arises, such as an extra 30% in archery or +50 in health.

Gotta be prepared in this game.

I prefer the ebony. I am not much into changing clothes other than for survival reasons.