The PS3 is one of the best and cheapest Blu-Ray players out, regardless of whether it plays games or not. What HiFi/Sound and Vision rate it five stars based on it's Blu-Ray playback alone.
It can also surf the net, rip and play CDs, SACDs, DVDs upscale beautifully, it will always be current with Blu-Ray spec (via firmware updates). You can even stream content from your PC. Soon they're releasing a dual HDTV tuner for it that'll allow you to record TV. You can even hook up external drives and use them. You can also install LINUX on it.
In short, if you are looking for a Blu-Ray player the PS3 is by far and away the best value for money. And that's without games in the equation.
I suspect the PS3 has had a lot to do with Blu-Ray winning the format war. It's a brilliant piece of kit overall, I love mine to bits. It's also surprisingly quiet, especially compared to my 360.
EDIT: I would just say that you should make sure you buy the Blu-Ray remote (around £15 if you look), using the control pad to control DVDs/Blu-Rays isn't ideal. But the remote is bluetooth, so you don't even have to point it. Brilliant!