I am in a minority but this has always been my favorite despite one or two tracks that I'm not wild about. Strictly speaking, this is actually a compilation, being made up of the tracks from the soundtrack EP plus the A and B-sides of various singles. However, as none of these tracks appeared on any other original Beatles albums, it is classified as an original album. - Because it was not recorded as an album, it sounds less cohesive than some of the other Beatles albums but the strength of the songs more than compensates for that.
Taking the soundtrack songs first, three of them are outstanding - Fool on the hill (a song that has been covered by others, sometimes brilliantly), Your mother should know (a fun song, as true today as it ever was) and the theme song. I can never make up my mind about I am the walrus. It is a piece of nonsense but it is very well done. Only John Lennon could have recorded such a song and not been ridiculed for it. There are times when I really enjoy it and there are times when I think it is rubbish. You must make up your own mind. Flying (an instrumental) and Blue jay way (a George Harrison song) are decent but nothing special.
The singles tracks are, of course, all masterpieces. The only B-side, Baby you're a rich man, is less famous than the other tracks but it's a classic as far as I'm concerned. You need no introduction to the four A-sides (Hello goodbye, Strawberry fields forever, Penny Lane, All you need is love) - you've heard them all countless times or you wouldn't even be thinking about buying this album.
Others may cite Sergeant Pepper, Abbey road or Revolver as their favorite Beatles album. I love them all, but not as much as this one.