Something like this should do the trick. It converts your analog 3.5mm connections to rca for tv and video games. My x-530's came with one but I know you can buy them too.
Are they good speakers and is it good enough for gaming on my ps3 and watching some blu Ray movies on my tv?
I love em. I used to have the z-640's which were the early series but I upgraded to these about two years ago. Very reliable and very good sound.
Depending on how big the room you have the tv is in I'd say they would work quite, well especially at the price point. It won't be any home theater system but very acceptable for a small-medium sized room and a single person (i.e. no talking or distractions)