Well, my first character in CT was Litchi, but this was before I even knew anything about the fighting engine. I did okay with her until my friend picked up Tager.
Trying to find a way to overcome the soviet damage, I looked up the special edition combo DVDs on Youtube. Ragna looked interesting, so I tried his stuff. It was too hard for me at the time, so I kept looking through the combo DVDs. Sooner or later, I stumbled across ν-13. Commence D-mashing.
When CS was released, I expected to be able to mash with λ-11. That worked out horribly. Then I discovered Challenge mode. λ was still my main, until CS2 came out. At that time, I saw a video of Jin's corner combo (with 623B and 623C) and decided to try his challenges. I've been best as him ever since.
TL;DR: ν because D, λ because Challenge mode, because corner.