I grinded smithing all the way to 100 to craft Daedric armor and weapons. (I know it only requires 90, but why not go the extra ten points while you're at it?) Then I got my Conjuration up to 100 for permanent atronachs. Followed by Sneak and One-Handed, which got to 100 out of normal use.

Smithing. Professional forger of Iron daggers.

I think it was smithing, then followed closely by one-handed and light armor

Sneak. It seems to go up faster than all my other skills, but that just might be because it has more utility and is therefore used more often.

Sneak. Other than in towns, when would you not be sneaking?

Yeah, it's a bit sad that you can become Skyrim's best smither through such simple repetition. I don't think I made anything but Iron Daggers until my Dragonscale set!

Sneak for dark purposes.

They really should've assigned different skill experience values to each item and material. As it is, it's more profitable and earns you experience quicker if you just make small iron and hide stuff unless you really need to craft some armor.

I think One-Handed was my first maxed skill on my paladin, Conjuration was the first on my Nightblade.

Sneak, then Archery, then One Hand.

Conuration because I used duel conjured swords the entire game and nothing else as a weapon.

pickpocket

Sneak, quite obvious for a nightblade.

Block. Goes up fast when Giants are smashing you.

Would have been Smithing but I intentionally capped myself to where Smithing could never be my highest rated skill.

Archery and then alchemy.

Block.
I bet no one here will say it is Restoration. That skill is a B to level up

sneak

Smithing, because dragon armour sounded awesome, but then it svcked. Sneaking was my second,

Sneak. By constantly sneaking around in dungeons to avoid having to fight too many foes at once, this skill easily reaches level 100 halfway through my game.

athletics, i didn't even have to do anything and i was jumping at a level 100.

You must be playing the Skyrim 'unstreamlined edition', my friend, because in mine there are no athletics skill, no medium armor neither spears nor crossbows!

I think it was sneak on my level 50 guy. Then archery, lockpicking, smithing. His light armor is at 96 though...need those last 4 ranks for the top perk. What's sad is; I have 100 lockpicking, but I never put any perks in it until a few days ago when I got the first perk for novice locks. I'm DAMN GOOD at novice locks, I tell ya.

Archery, smithing then sneak (in the same session yesterday. 50 hours into my second chap.

Thank you ogham infinium for those 10 level in archery and smithing.

none yet, but at the rate its going, its gonna be 1handed.

My latest character skills that reached the cap level of 100.

Sneak --> Illusion --> Conjuration (not 100 yet, but near)

By the way Illusion master spells are awesome, as you enter a dungeon and cast one master level Fury spell at once, then sneak into the scene to watch the grand scale battle around, as you regain magicka to cast other spells when needed.

The only drawback is that such spells reduce your character progression speed a lot, as you do not have to fight many foes ahead, and at level 100 illusion, you do not gain any experience from casting them.

This is like becoming master of a guild so that no more quests are needed for the guild, and you have to look elsewhere for more adventure.

My first playthrough was sneak.