I'm afraid I'm a bit anti-social D: I think I'd be blocking my entire family except my mom, sister, sister-in-law, and brother, and almost all the friends I know irl. I think if I started blocking people, I'd end up with mainly just a group of ffxiah'ers, 3-4 family members, and 3-4 rl friends. That wouldn't be bad of course, I'd just feel like a jerk.
I do have a question about blocking though. Say I blocked someone, and then that someone came and posted on my wall or replied to something I posted. Would I see that? Or would the block only keep me from seeing them spam the news feed? I'd want to be able to reply to them if they posted on my wall, just so they wouldn't necessarily know that I blocked them. I'm a big hairy coward and don't want to deal with the confrontation if they ever found out I blocked them xD so I'd have to be able to reply to some of the stuff they said at least.