I want a gaming desktop PC.
My budget is $600.
Are there any pre-built PC's that are any good?
My parents want to buy a new PC as a gift for me,
but they do not want pieces of a PC, they want a pre-built PC.
Am I doomed to have bad performance?
Not many "gaming" PCs go for $600, mostly due to the fact that a good gaming card alone is $150+. If you are OK with playing at less than High settings at high resolutions, take a look at ibuypower http://www.ibuypower.com/Store/AMD_FX_Quad-Core_DDR3_Co..., although from that base system you want to upgrade to a 6770 video card, and up the PSU to a 500-600 watt range for any future upgrades.