Xbox 360:
Pros:
Better online
Cross game voice chat
Open mic system
Most shooters are better on the console
Exclusive games such as Halo 3, Gears of war, Fable
Most multi platform games are better on the system
Reporting system in Xbox Live
Easy to remove hard drive
Cons:
High failure rate
Suffers from Red ring of death
Scratches discs
Proprietary hard drive, offered only in 20, 250 and 120 GB's
Cant upgrade hard drive beyond 250 GB
Can't take a off of the shelf laptop hard drive and use it with the system, due to way the system is designed
Noisy cooling fans
Power supply unit is not in the system, it is out side of the unit connected to the power cord
Power supply unit is large and bulky and may cause problems with the system if not properly taken care of
Uses outdated DVD format
PS3:
Pros:
Lower percent failure rate
Uses Blu Ray technology
Quieter than the Xbox 360
Has a higher capacity disc format that developers can take advantage of
Cheaper than the 360 in the long run
You don't have to keep replacing batteries for the controller like the Xbox 360
Has game exclusives such as, the Socom series, Metal gear solid 4, Killzone 2, Gran turismo 5, War hawk
Higher build quality than that of the Xbox 360
Built in power supply unit
Non proprietary hard drive that can be upgraded by the user to higher capacity's than 120 GB's
Any off of the shelf laptop hard drive that is a certain format, can be used with the PS3
Has a internet browser
Will surpass the Xbox 360 in graphic power when developers take full advantage of the system
PS1 games can be purchased on the playstation store, along side other games
Full PS3 games can be purchased on the play station store
Free online, that will only get better over time
Cons:
Playstation network not as good as Xbox live, as of now
No cross game voice chat