Re: How many times have you watched the different series?
Hard to guesstimate. I was watching TOS in the 1960s, so each episode was probably seen more than a dozen times during the following 20 years. I used to have the entire VHS collection, but only a few have survived. The only complete series on video I currently have is ENT, which I didn't get until this year (having missed most of the 3rd and 4th seasons in first run), so of that, almost every episode has been viewed at least 4 times. The exception is TATV, which I didn't see until this last January. I'm afraid to watch that one again.
Dr. Howard, Dr. Fine, Dr. Howard: For duty and humanity! --Men in Black (1934)