Re: If you were starting the Steelers from scratch and could keep only ONE player...
I picked Holmes, with Troy a close second.
Those are all great players, but if you're rebuilding a team from scratch, then you have to basically disqualify Hampton, Smith, Farrior, Harrison and Ward right off the bat, just because they're past the midway point of their careers. Nothing against them, but that's just an inescapable fact unless you think they'll be playing until they're 45.
That leaves Troy, Parker, Holmes, Woodley and Mendenhall.
For Mendenhall, it's too early to tell how good he's going to be, so he's out.
Parker, as we've seen the past 3 years, is not a back you can use in every situation -- and RB is one of the easier positions to pick up someone who's at least adequate. So he's gone.
Woodley is great, but we also seem to have an innate ability to develop great pass-rushing linebackers. So my hope is that we'd be able to do that with the next guy also, whoever he was.
That leaves Troy and Holmes ... Holmes looks like he can be a great receiver in this league for the next 10 years. We always could use someone like that to throw to, plus he's become a decent returner.
Troy is a one-of-a-kind talent, but I had to put him second because it just seems a lot harder for one man to carry the team on defense than on offense. You can avoid him, scheme around him, a number of things -- but on offense, you get to choose who's the playmaker.