I think Previn offers the most consistent cycle overall with Thomson (not Thompson) and Boult on EMI as runner-ups. Previn's 2nd, 3rd, 5th, 7th and 8th are some of the best on record. I cannot understand the praise that the Handley cycle is getting here. I was never thrilled with the audio quality of his cycle and the conducting also doesn't really sweep me away like many others I've heard. Boult's first cycle on Decca was pretty good despite the mono sound. Anyway, as I said, Previn gets my vote.