A nerd's lair; a bachelor pad complete with a computer on a desk with ready access to the Internet (where occupants spend the bulk of their time when not sleeping), world-canceling features such as a door or noise-reducing headphones, and a respectable number of comforting knick knacks (ie collectibles, south park memorabilia, Todd McFarlane posters, etc.).
examples include but not limited to:
Steve Carell's house in 'The 40 Year Old Virgin'
Josh Baskin's apartment in the movie 'Big'
The bat cave (that dude held on to everything)
your place (you know who you are)
"I don't shave when I'm chillin' in my nerdcave, get baked like everyday my birthday...." - mc chris
"dude, your place is such a nerdcave"
"awe come on"
"you've got more video games then a teenage asian kid"
"its not that much"
you've got a figure of....is that the six million dollar man's boss?"
"Oscar Goldman. Thats worth way more then Steve Austin"