[SOLVED] Which windows

Hello, so after successfully fixing my computer I would like to ask which windows would suit my computer best.

Basically I have windows xp, windows 7 and a really nice deal to get windows 8 very cheap.

Here are my specs:

Memory: 3072mb
Processor: AMD 64 X2 Dual core 3600+ (2 CPUs) @ 2.0GHz
Video card: Ati radeon HD 5450