"Best" is a very subjective term.
What exists is
1) at least 2 audience recordings. One of them is shit, the second one is acceptable. If you're lucky you can find the first pressing of the bootleg Free In The Park, which is cut, but has the best quality, it can be found on youtube (at least some tracks). Later pressings of Free In The Park has MUCH worse sound quality. Complete copies of this audience source can be found but they are again in much worse quality than the edited bootleg.
2) the video mix - all of them sound roughly the same, so unless you find a high generation copy from the 80's the chance is you have a best copy of this source
3) a matrix of the video mix and the uncut audience recording
4) a matrix/merge created of source 3 and officially released bits, shared here by The Real Wizard
For links use either queenconcerts.com or bokkepoot's database or the search function