What clothes/robes/armor do you think looks best for a Stealth/Archer character? I don't care about Enchantments or protection or anything, I mean just from a cosmetic standpoint.

I personally think Studded with some fur boots and fur gauntlets. Preferably fur. No helmet.

I think Thieves Guild armor is the best Rogue style armor in the game.

Linwe's.

Nightengale

Mostly agreed. The guildmaster set is perfect commando armor. For pure epicness, Nightingale Armor also looks amazing.

Hide, fur, studded, scaled or Underwear.

Leather doesn't look bad

Depends.

A wild hunter might make a fit for Forsworn or Skaal armor.

An elven war archer would do with elven or glass armor, you could use smithing perks for this as it fits the idea of a war archer in the first place.

And a sneaky type would do great with Nightingale armor.

Forsworn armour is good for any type.

Depends on the race IMPO

Hammerfell Garb for a Redguard
Elven armor for a Bosmer or Altmer
Chitin for a Dunmer or Orsimer
...

chitin looks terrible.
Dunmer look good in hide armour.
orcs look good in forsworn.

I generally use leather armour with either the novice hood and then the green hat ( its a hood ) when you come across one.

Pretty natural ranger type looking. If only the console versions had cloaks.

theives guild hood works with leather armour.