OK, definitely for these reasons:

_Sex
_Visiting my favorite shows and living them(I love Adventure Time, being inside of it is amazing!), and building up stories and relations inside of them.
_Seeing wonderful scenery and visionary arts and places, savory for my art hobby and definitely extremely pleasurable to watch.
_Doing all kinds of crazy fun stunts(flying, gliding, piloting a 747 through Tokyo while the kaydrous are attacking, ...)

Pretty much these, and of course meeting new friends here is a big bonus too!