Despite claims from Valve (and elsewhere) that the PS3 version of Portal 2 was the best, at least in terms of console versions, it looks like the 360 version has outsold it.
According to trade site MCV, the PS3 version accounts for 35% of UK sales, and the Xbox 360 version 54%. The PC version will obviously be more than is currently being quoted (11%) if you take into account Steam sales.
Whether this has anything to do with the recent PSN downtime is anyone’s guess, but it’s certainly worth mentioning.
Whichever version you went for (if any) Portal 2 is a fabulous game.