My doctor diagnosed me with asthma. Just checking - what's the best treatment.?

Combination... Most asthmatics will require a beta-agonist inhaler as well as a steroid inhaler. Other meds depend on the factors that contribute to symptoms in your particular case as well as the severity of your asthma. If you smoke, smoking cessation is an important part of your therapy.
Depends on severity. Asthma can vary in severity from mild to severe. Mild intermittent asthma is usually managed with short acting bronchodilators like albuterol (inhaled) on an as-needed basis. More persistent asthma (mild, moderate, or severe) is managed with daily inhaled corticosteroids in addition to albuterol as needed.
Albuterol. Most cases of asthma are treated with some form of albuterol. Inhaled using an inhaler or nebulizer. Aminophyllin has been used but tends to have more side effects. Sometimes steroids are used as an adjunct to albuterol.
Depends on severity. If you have intermittent asthma a bronchodilator like albuterol is enough. If you need that bronchodilator >2x/week, if you wake up with coughing or wheezing >2x/month, or if you have an episode of asthma requiring an urgent medical visit or if your require systemic corticosteroids >1x/year then you have persistent asthma. For persistent asthma you need a controller drug like an inhaled steroid.