I think 1-2-3 is great....IF you use it right! Recently, I witnessed a mom at a grocery store counting. She reached 1, then 2. The child blithely kept misbehaving. She waited a bit then said, 2 1/2!! Kid didn't stop. Then she said 3!! And the kid grew a halo and stopped. Then the mom said, "good, now don't do it again."  
 
I encountered them again on my journey down the aisles and, what do you know! Kid's at it again, and the mom counts fresh from 1. 
 
When you reach 3, that's IT. Game over, man. If you use 1-2-3, be prepared to ACT once you reach three. The idea is that the kid stops BEFORE three. Otherwise it's just another lame empty threat. 
 
I'm more like jettav. I say ONCE, then I act. My son is 1, and tests limits a lot. I am always consistent, because I feel that this age is crucial. If I am on top of him now, it will make 2 and 3 that much easier. Even now, people remark how well behaved he is. If I say, No, he will usually stop, unless he's a tired grump. But when he doesn't stop, he knows Mom's not afraid to pick his little diapered bum up and carry him away and stick to her guns! 
 
I guess I'm more Authoritative, at least now. 1,2,3 year olds have no business negotiating or being included in a "democracy". When they are a little older, then I will be more apt to discuss the "whys" of my discipline, but no may still mean no. I think lots of parents have the order reversed, they want the Democracy right away when their kids are toddlers. Then they realize their kids are out of control, and try to become Authoritarian during the preschool years, but the kids don't take them seriously anymore. Do it in the right order, it's MUCH easier.