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!
He was playing th "sarcasm" version of the game.....sheesh
Smithing for sure. It is exremely easy to level up and doesnt even need to use any "cheap" methods to do so. I also wanted to see the dragon armor as soon as possible.
Hit 100 in pickpocketing by level 28 on my thief character, but it ruined my character as I had no combat skills and ended up in a quest that required them and realized that I was screwed because I had outleveled my combat abilities badly.