Absolutely dreadful.
The game is populated by many of the Internet's degenerates, such as furries and Harry Potter fan-fiction writers. It has literally the worst community in any MMOG. Even Second Life's administration team has been infiltrated by these horrible people. I'm not lying when I tell you that one of their appointed new player teachers was in fact an 18-year-old male who believed he was a baby wolf and liked to wear diapers and was literally unable to formulate a sentence correctly. Yeah, that shows you how much Linden Labs cares about their community.
The fact of the matter is, ladies and gentleman, that the premise of Second Life looked great on paper, however Linden Labs has made it a cesspool that they use to make themselves rich at the expense of good taste. But the ultimate reason this game blows is that it is pretty much moderator free. Unless you set off an attack that hurts the virtual world (an act I applaud), there is virtually nothing the administrators can do to stop your actions. So that means that tons of sickos get to use the property they buy to store child pornography and copyrighted material. Second Life is truly the worst video game of all time, ladies and gentleman, and not because of it's horrible graphics, broken gameplay, and horrid controls, but because the idea that thousands of people support this abomination of a game makes me quite concerned for our future as a species.