I really dislike being pigeonholed into playing a predetermined list of characters. I think it's lame and a step back in gaming. It's simply personal preference, I know a lot of people like linear stories and all of that, I don't. The first time I started feeling satisfied with character creation was SWG. Before then, I hadn't seen anything like it; the sliders, the deformation of characters, such a range of possibility! Really cool, really fun. However, this stopped being rare and I started disliking how "meta" it felt. Sculpting your character is cool, certainly, though I think it can be improved. This is, of course, meaning improvements with adhering to immersion.
With that said, let's speculate on how the formula can be improved. Do YOU feel like it could be better? What would you want in your game? Does immersion start when gameplay begins or when you advance from the start menu?