Which drug you recommend or consider using as the safest anesthesia during upper endoscopy. ?

Depends: There is no such thing as safe or not safe drug. Each individual may have co-morbidities that may influence an anesthesiologist to use a particular drug, but the key is titrating whatever drug is used.

The safest drugs: are the ones chosen by your anesthesia provider after a review of your medical history, a review of your medications and an assessment of your physical status. There is no "best". There are ones that are appropriate to the patient and circumstance.

Anesthesia for endo: it is common to use a combination of Versed and Fentanyl or Demerol (meperidine hydrochloride) for sedation some physicians prefer Propofol it is a personal choice of the physician and depends on allergies or other medications you have been or are using

Depends: It really depends on your current health, risk factors and also who is administering the anesthesia. All anesthetics carry risks but your are safest in the hands of a experienced anesthesiologist.