The 20GB PS3 is a lot more capable than the core 360. The core 360 is actually completely *missing* a major component. All the 20GB PS3 is missing is wi-fi and a memory card slot - two things that the pro 360 doesn't have either, and which aren't directly related to gaming.
It was different when Sony originally planned to not include HDMI with the 20GB version. That would have made it a certified tardbox. But it's got HDMI, it's got a hard drive, it's got everything else its big brother has for games and video output, just no wireless and no memory slots.
I'd probably go with the 60GB myself if the difference is just $100, but if I could get a 20GB for $329, I wouldn't worry about what I was missing. I think the stuff the 20GB is lacking is probably worth about $120, so the 60GB is normally worth it... but wouldn't be if the difference was more than that. (Remember that the PS3 also uses standard hard drives, so you can always upgrade your 20GB hard drive later.) None of it matters for games either.
The pro 360 has 2 memory card slots. It also has a slot for a hard drive. THe only difference between the 360 models are the hard drive and what controller it comes with. Much easier to upgrade than the PS3, where you pretty much have to buy a whole new unit
Don't stop there, keep throwing out your bs and prove your absolute ignorance of reality.