Hmmm. I'm a sucker for being a wordy mother fucker when invited. So....
The short answer is that there are many types of trolls. Anyone who thinks they can define a troll in one sentence is deluded. This is why us trolls always laugh at forum board admins who make a sticky post that claims to identify and define trolls. Somewhat related but off-topic here is that trolls are always defined by outsiders as "needing attention."
In many cases, this is true, but it is not empirical. Certainly, the worst response to a troll is no response at all, so I can see where many non-trolls make the mistake of assuming we're all attention-starved basement-dwellers.
So, in the interests of avoiding a 15 paragraph response on "what makes a troll," let's assume for the sake of brevity that we can encompass trolling into the following: those who desire to shake up the groupthink and/or expand the focus of others to include unconventional thinking (this would then include spammers, flamers, issue trolls, humor trolls, etc)
Thus, when I ask about a "troll site," I am asking about a forum where like-minded trolls gather. I lost my home and have made one here, but TK isn't really a troll site. It's more of a "pwn" site. I need to find a real troll site, a home - someplace where other like-minded trolls gather to share and enjoy trolling other boards.