Thank you all.
Now I really need to study:-)
BTW, I've compared many of the recordings at youtube with the 1962 Nureyev/Tallchief performance in the NBC Bell Telephone series (available on DVD in his series with Erik Bruhn) and I honestly don't think they can touch that. I'd recommend that DVD to anyone just for this duet, in which Nureyev is absolutely great.
Nureyev at 24 has a charm, sleek body (he got a bit heavier later), speed and height which are amazing, IMHO.
The fact that he benefitted from Bruhn's help (which he had to replace on that night), both based on their relationship and the fact that this was a Danish work, might have counted for a lot in terms of the refinement and his deportment. Also, there's a special communication between Nureyev and Tallchief and the fact that they two had (another!) relationship at the time (if one reads Kavanagh's book one really sees everything as a menage a trois, at least for a short time) might have contributed to some of the radiance they have on this film/recording towards each other.
Other interesting couples, in the same piece, at youtube, are:
The great Yuri Soloviev and Alla Sizova (wonder about the year?)
http://www.youtube.com/watch?v=gr25NoQtWRE
Sizova seems to have been great too, great body, very graceful. First time I see her in a recording.
From the new Kirov, Obraztsova and Sarafanov:
A little light for my taste, Sarafanov, but great dancing.
From these mentioned in this thread, I like most Sizova from the females (and the diaphanous skirt helps putting her to advantage; also great arm work, perfect, refined, thin, body) and Nureyev in men, followed closely by Soloviev.