Favourite has to be Bigring VR, best videos I've seen. Most ridden is Zwift due to the training plans.
You can choose the sections of the video you want to ride, in BRVR, if you don't think you'll complete the whole video. Alternatively you can now finish an incomplete video. I'm not sure if it combines the 2 or possibly more sessions to provide a completed time. I've not done that yet.
With BRVR you can use the zwo files to train on the video rides now.