What's the most character customization you'd be okay with?

[Shurrikhan]

Specialization would be nice. Having similar abilities and having to decide between one or the other version.
But that has a high potential to become a nightmare if not balanced right, aka "OMG you n00b, you chose that skill? Grats on gimping your char lololol"

Then you just have to make it so utterly unique that no one knows what the other options were!