The PS3 has the 7900 in it. The 360 has the "xenos" GPU, which isn't like anything. Its similar to the x1900/1950 series, but like modern GPUs it uses unified shaders. Unlike modern GPUs, it can't run DX10 code.
Yes, the GT220 can play games. Seeing as its weaker then the 4670, this makes it to weak in my opinion. If you want to do PC gaming, you need at least the 4670, or the good 9600GSO. (assuming we are talking about 1680x1050, if your at 1440x900 or lower, obviously lower cards are ok.) Sure you can use the GT220, but you'll have to turn effects down/off, not use AA, suffer frame lulls, etc.