I'm using a 40/30/30 diet - the cutting version of the Berardi "Massive Eating" from T-Mag (there's also a hypercaloric bulking version.) Basically, you eat protein/carb meals for the first 3 meals of the day and protein/fat for the remaining 3. I'm happy with it so far, although I do get carb cravings in the evening sometimes.
I've tried ultra-low carb diets before and felt like crap after a couple of days - I get grouchy as hell on a ketogenic diet and I just can't have that at work, and my training goes to hell. My results on this are almost as good, but without the downside.