Thank you everyone for your responses. I'm enjoying reading these stories. Hopefully sometime soon I will have my own.

I have recently picked up Katarina and have started playing her almost exclusively. My only issue with her so far is that, well, I've only won one PvP match when playing as her so far. Perhaps I need to find a way to contribute more in team matches or something to earn those victories.

My progression of champs came to be from olaf to jax and finally to riven. Nothing like solo top love, with the possibility of jungling.

i dont really have a "main" champ, because i usually counter pick. but i main top as jungle for roles. my favorite champ for both is lee sin. i love him high mobility with his Q and W and lots of sustain. he has been my favortie since i think.....lvl 21 i think, so a while. but like i said, i dont get to play him a lot because i always counter pick.

Through the 5 months that I've been playing league, I've come to the decision that if i suck with a champ the first three games, I'll rock with them. With that in mind, I've had 3-3.5 main champs. My first main champ was TF. I thought he was the bees knees, but i played him AD so he sucked. I played him until the end of April. Then when i got bored of him i started saving ip for my next champ, Ziggs. He was the first champ I ever played. I had so much fun the 4th time I played him, but it was the last day he was free. so I saved up my IP for six weeks just so I could get him. We were inseperable. But then I hit level 17 and got bored again. I had always had my mind on Shyvana because she looked BA. I then tried her and sucked. What a promising sign for me. After game four, I knew we would be a beast team. Good thing she was on sale that week cause if she wasn't I wouldn't have her. Now I'm trying out Ahri, not because I'm bored of Shyv. but because I thought she would be fun. I have played about a dozen games with her and I can't do guano with her. Thats why I have 3-3.5 main champs. That's my story

My main is a beautiful beast with the grace of a swan. You guessed it: Nasus :) I love playing nasus since he's one of those champions that are very easy to pick up, but mastering him is beyond difficult, especially his early game. Hes one of the few tanks that can actually carry a game while still building almost pure tank (with the exception of trinity force which works really well on tanks anyways)
His early game is really difficult to get the hang of, you need to know how to farm really well without pushing on a champ built to push HARD. Instinct tells you to Q every minion as soon as they're low enough to kill. Don't do that. You need to kill them right as they're about to die anyways (I usually kill when they're at 20 hp or less to make sure a minion doesn't just randomly steal it)
His late game is pretty simple though: run through the enemy team, wither the carry, Q, win.

The champion I slogged through levels 1-30 with was Sivir. I was inspired primarily by [Guide] God Tier Aura Sivir

I've had some amazing runs with her. including a delayed penta. But that spell shield man. Love baiting with it, and I still love that feeling when ricochet bounces down the line of minions to deal that last bit of damage to a fleeing foe.

For me the How became my main really came down to who I was both having fun with and doing good with reliably. She is very straightforward and will just destroy you if you try to go toe to toe with her. No Muss No fuss, Little in the way of CC but just brutal damage. I love my shyvana, Been playing her since release. Top as a tanky bruiser into a full tank as well jungle. But Im also working on Darius. I love my Brutal damage dealers. Volibear is the third one I consider a main again in the same vein. Beefy with a side of RAWR YOUR FACE! Gotta love it.

When i started i looked at champions for goals and decided to BUY CASSIOPEIA FIRST! What was i thinking?, I dont know my first game was actually good and loved her abilities from the start. Today she is one of my two mains. The other Karma was actually a good decision as well. My first game i was called a troll beacuse i used a graveyard champion. I loved how i did my second game 6 kills 0 deaths and 22 assists

I'm not sure when my main become my main. I just know when I use certain champion, I have better chance to win and I consider that champion is my main.