Wilkinson Sword Extreme 3 Beauty razor (disposable) is what I use. Most supermarkets have them and they're the best shave I've had on my face and my balls. Most of the rest of me is epilated, but if I don't do that for a while I use the razor all over to catch up a bit.
I use ordinary unscented soap with the razor as I find all the chemicals in shaving foams, shower gels or hair conditioner makes me red if I wet shave every day. After I've soaped my face or balls, I rub the razor along the soap bar before each scrape for extra smoothness.
I have some electric razors but I've never been happy using them on my scrotum. Doesn't seem to work too well.