PSP Help and Confusion

Ok, so I am thinking of getting a PSP. I got 220 dollars for Christmas and I am a little confused. I have been hearing a lot about some PSP makes that are not as good as other, ever though they are more recent. I would just like to make the best possible choice with the money I have. Any help would be appreciated. Also, if you know of any games that good to start with, please tell me. Thanks!