Bee Gees: 1st (1967)
Their 1967 debut was far more indebted to the Beatles than most of what came later, and while this makes a few songs a bit derivative, the Bee Gees were often better served being derivative of the Beatles than carving out their own ground. Take "In My Own Time," a punchy little pop tune that sounds like a Rubber Soul-era outtake, and a damn good one at that.
As was mandatory for most British (or, in this case, Australian) bands in '67-'68, there's a large debt to Sgt. Pepper and like-minded pop-psyche. Opener "Turn of the Century," "Red Chair Fadeaway," and "Craise Finton Kirk" are all whimsical and of the moment; and they venture into outright psychedelia on the trippy, Moody Blues-ish "Every Christian Lion Hearted Man," odd Gregorian chants paired with an infectious chorus that was arguably borrowed by a little-known band called the Clique on their non-hit "Superman" (later covered by R.E.M.).
You've also got a few better-known singles: "New York Mining Disaster 1941" is perfectly fine, a little dirge-like but with a catchy chorus; "Holiday" is way too saccharine for me (a weaker cousin to the Stones' "Ruby Tuesday"), an indicator of the sound they'd pursue on their largely interchangeable soft rock albums in their pre-disco early '70s. Alas, much of the balance is similarly sappy and often string-laden, not something I have much appetite for.
Still, a chunk of this is charming enough, a ratio that would carry over to the next three '60s releases, each of which had a few surprisingly colorful sunshine pop/light psychedelia tracks (particularly on 1969's impressively ambitious Odessa) amidst the more cloying work. Personally, I took these highlights and made a pretty great mix of psyche-era Bee Gees, something surprisingly cohesive. If you're a fan of early Moody Blues, maybe the first Genesis album, odds are you'll like some of this stuff as well.
Here's "In My Own Time":