I see three main groups of “SEOs”.
The first group, the link builders, focus their energy on building links to their sites. Every link counts for them. They know all about PR and how the juice flows. Black and Gray? Yes, unnatural link building is common (Google’s penguin algorithm update is supposed to penalize the worst link spammers).
The second group, the technical SEO gurus spends all their time of thinking of new ways to improve their website’s code, structure, performance etc… Black and Gray? Yes, but difficult now since the search engines are a lot smarter than they used to be…
The third group is the content creators who create what you read and see on your screen. If you’re this kind of SEO, you research every word you use. You analyze page titles, meta descriptions (you care about click-through rate). As with the other groups, there are gray and black hats here too. They will do anything to get new content. Black or Gray? Yes for some it doesn’t matter if their content is “spun” or copied straight from other sites (Google’s panda algorithm update took care of some of the worst content thieves and sites with poor content).
What group/groups do you belong to? Of course the perfect SEOs belong to all three.