Well, if the camera is your only thing you need, then go with the w959.
Better question to ask yourself is "What do I need out of a phone?"
Don't base your phone decision on the camera. Took at battery life, texting, internet, bluetooth, and/or whatever else you use the phone for.
I think you'd better go for the w595 after I read this : "Sony Ericsson have spent a whole year fixing the bugs in the W910i firmware, and the new firmware is so much better it weighs an extra 20 grams. Mystery solved."