I'm still gaming most of the time on PC, but I do own a PS3 and 360. 4 main reasons.
- Co-op games like Lego franchise and Rockband
- Exclusives like Killzone 2, Uncharted and timed exlusives like Mass Effect (I usually trade in and buy on PC later :: )
- Ease of use, no install, few crashes good if after a long day and just want to kick back and play and Media playback, Blu Ray, just works.
- I can afford it now :: Not a real good reason, but it works for me... Well actually a PS3 + a thrown together HTPC is cheaper than building a dedicated HTPC good enough for BD and gaming.