1st pressed vinyl best ones to get ?

Agreed with the RL mastered version of LZ II.  Many original Robert Ludwig Sterling and Masterdisk mastered first pressings are the ones to get.

As a general rule, first pressings are best, and I generally dislike reissues, particularly the half-speed ones that sound phasey, thin, and compressed.  They often use equalization through RLC circuits that add phase distortions.  Later masterings usually fail due to degraded master tapes and/or loss of mastering techniques that were superior originally.

Getting a pressing from the country of the artist often works but there are many that don't follow that rule as far as the best pressing.  I think a better way is to look on Discogs and learn the parent record company, as the highest generation master tape usually stays in the country of the parent company for mastering, while lower generation tapes are sent overseas for mastering in that country.  I learned this when a US A&M pressing of Cat Stevens Tea for the Tillerman significantly beat a UK pink Island pressing.  Obviously the highest generation master tape was done by A&M, probably by Bernie Grundman.

Sometimes a second or third pressing can beat an original, but I usually look for the mastering house in the trailout.  If it comes from RL, Sterling, Masterdisk, Kendun, Precision, Bernie Grundman, The Mastering Lab, and other independent mastering houses, these are usually sonically superior.

whart, thanks for the info.  So Island was the parent company but A&M either did a better mastering job, as they were wont to do, or received a higher generation master.  I agree that there are no hard and fast rules and many exceptions, but I stand on my argument that finding the parent record company is a much better predictor of optimal sonics than the country of the artist, based on, yes, listening.  Just listen to ELP for instance.  The UK Island pressings sound best except for the first album, for which I found a Cotillion that sounds far better.  There are also pressing variations within the same matrix, so sometimes this will lead to exceptions.  A good example is ELO.  There is no rhyme or reason for which pressing sounds best.  Sometimes US, sometimes UK.  Of course, we could argue all day what we think is best :-).