I'll echo Rev on why I prefer the PS3. Prefer isn't a strong enough word. I VASTLY prefer the PS3 to the 360. But that's a topic for a different thread.
I agree with pt. It's now two years into the 8th gen and that's the PERFECT time for collectors to complete their 7th gen collections. It's true that some XBox and PS2 are still cheap, most of the good stuff bottomed out years ago and have been on the rise for a while. I'm still looking for an affordable copy of Stubbs the Zombie, for example.
But the important thing with gen 7 is those games are dirt cheap at RETAIL. You don't have to sift through the Internet or get lucky with a local Craiglist deal. I was late to the Original XBox party (got mine in 2015) and I had to check CL daily to get the 60+ games I have for it on the cheap. I know that's not unusual for collectors, but the thrill of a score never seemed to outweigh the inconvenience. Again, another story for another thread...
Now is definitely the time for PS3 and 360. The prices are at the lowest that hey will likely ever be. I have been lucky enough to hit the "4 for $10" sales multiple times and I have almost everything I want from the entire generation. And I know for a fact that GameStops around the nation are trying to dump their stock. They're almost out of Wii games. Get the PS3 and 360 stuff while you can!