BotoxAgent said:lately, my second alt has been Ryu. He's a basic, pretty solid character that relies on fundamentals and not too much on gimmicks. Using him kinda gives a platform/skillset from which to experiment with other characters.
I've thought about this as well.
On a side note regarding fundamentals, at a theory level I knew there are character agnostic fundamentals, but when I had only seriously played and gotten into it with one character (Rufus) I never really experienced it. After picking up Yang, I notice improvements when I go back to Rufus even if I'm just messing around. It definitely surprised me.