I didn't buy the PS3 because I already had an X-Box 360, which launched much earlier. If the PS3 had launched first, I probably would have had that instead.
That said, I don't really find the two systems to be significantly different enough to justify (in retrospect) spending more money on the PS3 (assuming they both came out at the same time). I don't play much online multiplayer with consoles, so it's really not a selling point. I have no interest in handhelds, so handheld connectivity isn't a selling point. I have no interest in motion control gaming, so the Move isn't a selling point. I HATE 3D anything, so not a selling point. The Blu-Ray player, while nice, also isn't a selling point since most games aren't going to take advantage of that very much, and I'm not going to pay twice the price for a movie to get it on Blu-Ray so I can get a picture quality increase that I won't notice and DVD/Digital copies I don't want.... so no, not a selling point.
Additionally, I can't stand the Playstation controller. Maybe I have freak hands, I dunno, but Playstation controllers have always been super uncomfortable to me.
The exclusives are really the only selling point... and even then, I'm not interested in the majority of them.
I'm not calling it a bad system or anything... it's just not the right system for me.