I use freederm and although it is pretty expensive (£10 for a small, and I mean a small tube) its does the job. Every time I have one of those huge red spots that can't be popped, I just stick on a little freederm and the spot looks much better a couple of days later.
But if you have proper acne then go and see the doctor as other people have already mentioned. I only have outbreaks every couple of weeks, where I get a couple of spots but they tend to go within a week or so.
Man I hate spots. I hate them so much.