PS3 Is free online play and a blu-ray player and the past has proven it's more "durable" meaning not to many problems such as red ring of death
Xbox 360 has a better online system and thats all i know that is better about it.
Wii is more about game play and has alot of family and mini game type games.
PS3:
Units sold 50 million (as of March 29, 2011)[2]
Media
Blu-ray Disc (PlayStation 3 game disc)
DVD
Compact Disc
PlayStation game disc
PlayStation 2 game disc (1st & 2nd generations only)
Super Audio CD (1st & 2nd generations only)
Digital distribution
Operating system XrossMediaBar
System software version 3.60
(March 10, 2011; 44 days ago)[3]
CPU 3.2 GHz Cell Broadband Engine with 1 PPE & 7 SPEs
Storage capacity 2.5-inch SATA hard drive
(20 GB, 40 GB, 60 GB, 80 GB, 120 GB, 160 GB, 250 GB, or 320 GB included) (upgradeable)
Memory 256 MB system and 256 MB video
Display
Video output formats[show]
Graphics 550 MHz NVIDIA/SCEI RSX 'Reality Synthesizer'
XBOX360: Units sold Worldwide: 50 million (as of January 6, 2011)[3] (details)
Media
DVD, Compact Disc, Download
Add-on: HD DVD (discontinued)
CPU 3.2 GHz PowerPC Tri-Core Xenon
Storage capacity
Storage mediums[show]
Memory 512 MB of GDDR3 RAM clocked at 700 MHz
Display
Video output formats[show]
Graphics 500 MHz ATI Xenos
Sound
Analog stereo
Stereo LPCM (TOSLINK and HDMI)
Dolby Digital 5.1 (TOSLINK and HDMI)
Dolby Digital with WMA pro (TOSLINK and HDMI)