Games are cheap and include notable titles, it has HDMI and so looks decent on modern TVs (unlike the PS2 and Wii), it can play DVDs and Blu-Ray discs, and as the firmware isn’t being updated, you can jailbreak it without playing cat and mouse with Sony.
It helps that (most) games for it are really cheap pickups, and you can't play a large portion of the library on modern systems. I still have a ps3 backlog.
Played Raven Softwares' last game before being turned into a Call of duty helper studio a few weeks ago. "Singularity." Nothing to write home about, really not worth spending time and money on a remaster but a fun weekend of a unique story (time travel sovietpunk shooter) that only cost me about 4 money's with shipping.
There's still a lot of fun to be found in these old boxes.
The teen room at the local public library has a PS3. Kids seem to enjoy it. Although admittedly they did just get a new XBox and that's more popular right now. But it's also new.
Many (most?) are capable of being jailbroken with just a software hack too. I re-purchased a PS3 from a Craigslist ad expressly for that purpose. They are fun to play with once jailbroken with many interesting homebrew apps available, including emulators.
If a game is listed as playable on rpcs3 the game is pretty flawless to emulate. But, some games like mgs4 and infamous series are buggy and don't have good performance, so that's when I turn to the actual hardware.
The thing with the PS3 though is most games don't even get good performance on the original hardware. With the speed at which PS3 emulation is improving I've no doubt it will be THE way to play all PS3 games fairly soon.