I've bought several from ITVV. If you only want one DVD, get Concorde (5 1/2 hours, 2 discs). As an interested non-aviator, I find the whole experience amazing: the workload, professionalism & still lots of spare time & mental capacity to chat to the multiple cameras on the flight deck.
If you only want two, also get the Virgin Atlantic 747/400. Again, huge amount of talking to camera by the crew. As with very clear explanation of many procedures. I also have the Virgin 747/200 - again very good, & nice to see the older technology.
I've watched these three many times, & often just dip in at random just for the fun of it.
I also like their A320 simulator DVD, showing dealing with engine failures etc. Those 4 are IMO the best (I've not seen them all). A couple of the ITVV others don't have the crew 'patter' - they're just doing their jobs & not talking to the cameras about they whys & wherefores.
Hope this helps.