Gozo thinks that the best Genesis albums ever, or at least the ones most worthy of respect, are The Lamb Lies Down on Broadway, Nursery Cryme and Foxtrot.
Genesis albums predating Selling England by the Pound sound to me like they were made by a bunch of kids who would have been playing Dungeons & Dragons had they been born a few years later. (Not that there’s anything wrong with playing Dungeons & Dragons. Awesome game, it was.)
The Lamb Lies Down on Broadway: As you know, this is a double-LP concept album and is supposed to be about a Puerto Rican kid who somehow is transported to an alternate reality where he searches for his brother John, who may or may not be a real person. There are some great prog-rock riffs, but it’s saddled with nonsense lyrics at best (written by Peter Gabriel while he was dropping LSD), and at worst the lyrics are downright horrible. The first LP is mostly pretty good, but the second LP has a lot of weird sound effects and those downright horrible lyrics I mentioned earlier. The other members of the band kicked Peter Gabriel out after that album (or something like that).
The concert footage above, with post-Peter-Gabriel Genesis playing “In the Cage” from The Lamb Lies Down on Broadway combined with a medley of prog-rock instrumentals from Wind & Wuthering is pretty epic. I love how Phil Collins leaves the lead-singer station during the instrumental section and heads over to the drums. There’s a similar live version on the album Three Sides Live. The live version is far better than the studio albums.
The three best Genesis studio albums are Selling England by the Pound (the first album in which Genesis finally matured), Trick of the Tail and Wind & Wuthering (the first two albums after Peter Gabriel left). The quality of Genesis degraded after Phil Collins pushed them away from prog-rock to a more jazzy/pop sound. I never listen to any of the albums after Abacab.
Best live albums, both awesome albums, are Seconds Out and Three Sides Live.