If there is an absolute best in the genre of live albums than there is only one that deserves that title - “Made in Japan” by Deep Purple. Why? First of all - the band is superb. These concerts showcased the masterful musicianship of all the individual members, as well as their impeccable functioning as a unit. Second - it grossed more than any live album before, climbing the charts as an album but also with several singles, some of them being in the charts along with the studio versions (Smoke on the Water for example). Third - the recording, the mixing, and the overall production were something unheard until then. Live albums were usually made to conclude a record contract and the mobile recording equipment weren’t even close to what we have today. Even Deep Purple themselves didn't’ want to release a live album, especially not in USA and Europe. But after a lot of insisting by the Japanese organizers, they agreed to permit the recording of the tour, but they would let them publish it only if they liked it and only for the Japanese market. Hence the name - as Jon Lord stated, products that had the label “Made in Japan” were considered to be of lower quality back in those days (unlike today when we would actually beg for a product that wasn’t made in China). However, when they heard the quality of both the recording and the performance, Deep Purple immediately changed their minds and released the album worldwide. It was an immediate success, both critically and commercially.
OK, I know that In matters of taste, there can be no disputes, and there are many live releases that can be dubbed “best.” So let me rephrase my first sentence: If I had to choose an absolute best in the genre of live albums than there is only one that deserves that title - “Made in Japan” by Deep Purple!