The most commonly used AAS in medicine are testosterone and its various esters (but most commonly testosterone undecanoate , testosterone enanthate , testosterone cypionate , and testosterone propionate ),  nandrolone esters (most commonly nandrolone decanoate and nandrolone phenylpropionate ), stanozolol , and metandienone (methandrostenolone).  Others also available and used commonly but to a lesser extent include methyltestosterone , oxandrolone , mesterolone , and oxymetholone , as well as drostanolone propionate , metenolone (methylandrostenolone), and fluoxymesterone .  Dihydrotestosterone (DHT; androstanolone, stanolone) and its esters are also notable, although they are not widely used in medicine.  Boldenone undecylenate and trenbolone acetate are used in veterinary medicine . 
If you do not know what you are doing (. you used steroids with the most side effects, you abused the dosage, etc) then not only will you get bad side effects during the period of use, but you also will also get worst side effects after the use. Again, the degree of side effects is directly proportional to the dosage and type of the steroid and also dependent of the genetic propensity of the subject to get such side effects. Therefore, it would be impossible for me or anyone else to exactly predict what kind of side effects a user might encounter during a period of use. However, one thing is for certain. If you abused the drugs by using super high dosages and for very long periods of time, you may never be able to re-establish natural testosterone production, so you will then need to get with an endocrinologist and possibly stay on low dose testosterone therapy for life.