Could you tell me what's the best medicine for cold/allergies?

Treating congestion: Cold/allergies are usually a very vague and general term to descibe of nasal congestion, runny nose, cough due to post nasal drip and headache if there are sinus infections. Depending what causes it and how severe your symptoms are, best treatment can be different. If you can be more specific, it would be helpful. Otherwise, you should see a doctor to be evaluated to see which treatment is best.