I've had asthma for over 20 years now and I've always had to use an inhaler on a regular basis. I've always used Albuterol, but recent complications with money and medical have forced me to try Primatene Mist, a popular over-the-counter asthma inhaler.
While I don't think it's as effective as my prescription Albuterol, it's close enough to get the job done. If I'm having a particularly bad episode, I'll take more puffs than I normal would have with my standard inhaler, but other than that, it's still an effective way to control asthma and breathing abnormailities.
My only complaint - and this isn't about the medicine itself - is that the actual inhaler portion gets incredibly dirty after only a few uses. I strongly recommend taking special trips to the bathroom or kitchen to clean it out after every use.