There's some kind of a mistake in your headline. It is in fact impossible to buy "a new console", as all the available models are at least based on 5 year old designs, and specs haven't changed much in this half-decade. Your trigger finger might be itching, but it's really not the best time to buy a console. I don't know the console market as much as I used to, but I seriously think that after such a long time, "the next generation" is just around the corner. So,
used console instead of new one is the right thing to do. You name a lot of games which are available both on console and PC, but eventually, you will have to decide which mode of control fits you better to get your question answered.
That said, if you're choosing between PS3 and Xbox360... get a PS3. It's obviously the console for Telltale Games.