--------PS3----------
-Much better graphics
This is a lie sold by Sony to hide the fact that their console is a joke.
Memory
PS3 - 256 MB dedicated video, 256 MB dedicated RAM
360 - 512 MB shared in an intigrated configuration
360 wins hands down because virtually no game uses the full 256 MB RAM the PS3 has. The spare memory in the 360 can be allocated to better graphics (higher resolution textures) without any performance penalty. Exceeding the 256 MB decdicated video memory in the PS3 totally smashes the graphic system I/O bandwidth and degrades graphic memory performance to the point that it is not fesible for prolonged use (outside of the occasional peek load). The result is most PS3 versions of multi console games have to use lower resolution textures or enforce higher real time texture compression.
Processor
PS3 - Cell processor with disabled processing elements for yeild and dedicated processing element for OS. Only 1 single powerful processing element and many smaller lesspowerful processing elements.
360 - Cell based processor consisting of 3 main processing elements from the Cell with additional hyperthreading like technology. 3 powerful processing elements with hyperthreading like technology allowing for reduced cycle wastage.
Tie - Although the 360 has fewer, it has strong and although the PS3 has weaker it has more. The result is they perform the same on average when gaming. The 360 wins in games with focuse on few threads with high load due to it being able to provide more effort to single threads (such as most games). The PS3 wins in games which rely on heavy parallelisim where thread load is highly scaleable and no single thread requires a lot of effort (such as complex physics models which only PS3 platform only and some PC games use). A winner can not be decided as although the 360 is easier to program for and performs better on many cross platform games the difference is so minimal it accounts to situational dropped frames and most games are bottleknecked by graphics long before CPU is a problem.
Graphics
PS3 - Performance Nvidia Geforce 7 GPU enhanced and positioned for slightly more performance than its desktop counterparts.
360 - Highly intigrated custom designed AMD (at the time ATI) GPU system which uses technology used one some of their more modern desktop GPUs (ones released after the Geforce 7). Although computationally slower than its PS3 counterpart, it makes up for it with its more intigrated nature allowing for extreem optimizations.
The 360 wins this round but barely. Most crossplatform games look better on the 360 than on the PS3 including many ones designed on the PS3 due to optimizations such as free full scene anti-aliasing (which is far too computationally intensive to use on the PS3). The PS3 however does have grunt GPU performance allowing it to handle much more complex scenes (more geometry) than the 360 but this is only exploited by PS3 dedicated games or more modern PC games.
Game Medium
PS3 - Full blu-ray player
360 - Standard DVD
PS3 wins hands down. Although its largly a wholo victory as no PS3 game truely exploits the extra space blu-ray offers as they generally use excessive caputed multimedia (lowcompressed audio / 1080p cutscenes) or fill the remaining space with rereleases of old games. Playing blu-ray movies I can see as an advantage but that is losing its value as player price decreases.