Absolutely strongest reason. Bluray. I was wanting a game console (which I was leaning towards the PS3 anyway for God of War series, Resident Evil, Metal Gear and Final Fantasy all of which I knew 100% for certain I could get on the PS3). At the time it was still pretty expensive to get a PS3 ($500).

So, my plan was to hold off for a little while, but I just got a new TV so I wanted a bluray player definitely right now.

So, I'd say bluray was my biggest reason for buying a PS3 *WHEN I DID* though I would have bought one in general at a later point in time even if it didn't have bluray.