I'm asked all the time by followers of Cesar Millan and believers in force-based training, why I think positive reinforcement training is better. I'm not a dog trainer but I know the answer.

I often say: "Think about the way guide dogs are trained, or search and rescue dogs, or cancer detection dogs. That's the kind of dog you want, and that's the kind of bond you want." It's that simple. You want a dog that trusts you and respects you. None of those dogs were trained through force or "dominance". They each learned their craft through positive reinforcement. I promise that you will not fix anything by pinning your dog to the ground or poking it in the neck. Think about it: A leash reactive dog begins to growl at another dog in the distance and you two-finger poke him in the neck. What's the message being received? "Every time I see another dog, you startle me with a poke in the neck, so I guess I need to be on my guard from other dogs and from you."
Why not try conditioning your dog to look to you for guidance when another dog is approaching? And teach him that seeing another dog, means that something great's about to happen? 

I know this works because I've done it with my own 10 year old terrier. We work on this a lot. In the past few months we've closed the distance which we can pass another dog without a fuss, to a sidewalk's width. Not every single time, but most of the time. I'm proud of what we've accomplished together, and I swear to DOG, he's happier these days than he's ever been. And don't forget how positive reinforcement helped Cami emerge from her shell and allowed her to finally be a "pet".

How about the person who "alpha rolls" his dog? You'll likely notice that his pooch has poor recall. It could be he's learned that when he does come, he often gets a yank on the collar, rolled and pinned to the ground, or "bah'd" at.  Dogs like stability, and this behaviour from a human is anything but stable. Not only can positive reinforcement training develop a strong recall that could save your dog's life, it'll enhance his life. Dogs crave metal stimulation and really want to know they're pleasing you, both of which this style of training will provide. Which means your dog's personality and all his character will flourish. 
Don't get me wrong, I was just as mesmerized by Cesar as the next person, when his show began airing. But common sense rapidly took over and the bottom line is positive training has been researched for decades, and the methods are based on cruelty-free, scientific findings. For more information about how truly flawed "dominance" based methods are, I refer you this article. Not only is it extremely well written (by a certified trainer), there are numerous additional links to valuable information. 
On TV, watch It's Me or the Dog instead of watching the Dog Whisperer or that other guy who's name I'm afraid to mention. Want alternative reading material on the subject? Look for books by people like Patricia McConnell, Ph.D., Certified Applied Animal Behaviourist (my favourite is The Other End of the Leash).
If you live in Toronto and you need a great training school, there are a few: When Hounds Fly has two locations, and Who's walking Who has four. They're both based in positive training but they use different styles so please read up on their websites and see which one you think fit's you and your dog the best. Always check the credentials of anyone calling themselves a 'tainer' or 'behaviourist' and if you're not 100% comfortable with their methods, move on.