PS3 lets me play online for free. Later consoles don’t.
PS3 plays CDs and stores media files on its internal hard drive. Later consoles are limited to external storage solutions for media playback (and no, streaming doesn’t count).
PS3 has a snazzy user interface. Later consoles have… a user interface, I guess.
PS3 plays PS1 disks. Some models even play PS2 disks. None of the later consoles do that, having a strong reliance on digital downloads for PS1 and PS2 compatibility, meaning some games are straight up limited to the earlier consoles.
PS3 even lets me transfer games and media to a PSP or PS Vita through a USB connection. Guess what, the later consoles straight up don’t do that.
Don’t have an HDTV? PS3 works with composite, component, and even S-Video in addition to working with HDMI. It even downscales Blu-ray Disks to fit on your super small screen. Got an HDTV? PS3 upscales your DVDs to fit your super big screen. Later consoles only work with HDMI, and I’m not sure if the upscaling/downscaling thing with DVDs and Blu-ray even works or not.
The choice is yours.