Gustav Leonhardt's Goldberg Variations, recorded in 1978, are regarded by many as a classic version. It's hard to disagree: Leonhardt is a very fine interpreter of Bach and here his harpsichord playing is at its best. His tempi are generally moderate but never dirge-like and Bach's music dances most satisfactorily where it should - Variation 7 (Al tempo di giga) really does sound like a jig, for example. The more meditative variations are extremely sensitively played, as are the opening and closing Arias. It's a lovely interpretation.
My one reservation is that Leonhardt is ruthless in omtting repeats - I don't think there's a single one - which makes the whole work last just 47 minutes. Compare this with Angela Hewitt's 78 minutes plus, for example, and you see what is missing. I found this a bit disconcerting, but I must say the quality of the musicianship is a great compensation. If you're looking for a harpsichord version of the Goldberg Variations I can recommend this disc, although at a similar price Trevor Pinnock's fine recording (Bach: Goldberg Variations; Italian Concerto)is also a strong contender.
You may like to know that this disc is included in a magnificent, mega-bargain 50-CD box commemorating the 50th Anniversary of the label DHM. Deutsche Harmonia Mundi 50th Anniversary Box If you can run to a few extra quid you get this very fine disc and 49 others, too!