I've watched the original Star Trek TV series as long as I remember. In the early days of syndication, WUAB Channel 43 ran the show using film prints of terrible quality. I've seen the original Trek on VHS, Laserdisc, DVD, and now Blu-ray. The picture quality improves with each new format, and the Blu-ray has the benefit of refurbished sound and new visual effects.
My review of Classic Trek on Blu-ray