The Gulda (Amadeo 1967) is the most recent of a few great Beethoven cycles I've been playing since I got started in classical music early in June. The Kempff early fifties mono (I posted about buying it in this thread, never really played much of it until this year) was another - but I think my top favorite is Schnabel (I've got the EMI box, sound didn't bother me).
Gould I found most enjoyable, too (not quite complete though), and also Solomon with the late sonatas (a little less so with some middle ones included in his ICON box).
From Arrau, I have what's in his ICON again, and some of it was fine, I thought, but I found his Liszt better, and Mozart sonatas mo' better than his Liszt (though I do love Gould's Mozart sonatas, too - totally different, but wonderful).
Rubinstein's Beethoven is kind of weird. His mid fifties and early sixties recordings are the best (speaking only of his few Beethoven sonatas recordings), but they're not quite up there with Schnabel, Gould, Gulda, Kempff, I think.
Horowitz is pretty weak I found, but the few by Gieseking I've heard so far are again most wonderful.
A lifetime of enjoyment? I guess so! It only started a few months ago and Beethoven (violin sonatas first, then piano sonatas, piano trios, string trios, the violin concerto a few other thigns) was played most often by a big margin in the first two months.