Which pimple cream is more effective?

When I was very young, my brother told me of his schoolmate who suffered from really bad acne. The teenage boy went to consult a dermatologist who provided a very harsh but effective treatment for acne. The treatment was so harsh, the skin on his face dried, peeled and cracked after that.

Since my skin is dehydrated instead of oily, I have never suffered any major problems with acne. I get one embarrassingly huge pimple right on top of my nose every once in a while though, so I still need to know the various acne treatment available.

I have noticed that despite the huge price difference between various brands, most carry the same percentage of salicyclic acid and benzoyl peroxide. Despite that, some of my friends swear by Proactiv which apparently works when others don't. It really bothers me when I spend a lot of money in something that it doesn't work for me, for that reason usually I try tu use some free samples before I choose to buy the product.

Is there a difference between the various brands I’m not aware of? What’s your experience?