I hate it when people recommend the Beatles but don't actually recommend specific albums and talk about them. Fuck that. I'm talking about Beatles now, you metal-obsessed fucks can go on complaining about the 'incorrect' ways in which others are classifying metal and I'll do something closer to what the opening post asked.
Please Please Me - My favorite Beatles album. They were young, they were still friends, they were fun, they were shit hot. You dance to this, you sing along with this, and you sing it in two-part backing harmony with a lead vocal. It's the catchiest fucking music in the known universe and you don't ever question it for a second. It's simple and pure and perfect that way.
With The Beatles - More complex chord structures and meters. Call and response between lead and backing vocals on the very first track. "Till There Was You" basically tells Frank Sinatra that he's a fuckwad for judging the Beatles so hard, and Paul shines like a diamond. I've never cared much for him, but this is hands down his best vocal work. The production on this album is pretty ace, and they do some great Motown covers on here.
Meet The Beatles (US) - Half of the same stuff as With The Beatles but also includes "This Boy", "I Saw Her Standing There", and "I Wanna Hold Your Hand". Three songs you have heard of no matter where you live.
Rubber Soul - Getting more complex, lyrically and musically. "In My Life", "Girl" and "Nowhere Man" all stand out. And fuck you I'm not talking about goddamn "Norwegian Wood", I hate that song, talk to someone else about it if you really must.
Revolver - "She Said She Said", "Good Day Sunshine", "And Your Bird Can Sing", "For No One", "Taxman", "Tomorrow Never Knows", "Here, There and Everywhere". All on the same fucking album.
I don't even have to finish their discography. Hell, I even skipped a few albums and went out of order, and I never got past 1966 because even the most plebian of shitheads can talk about the White Album or Abbey Road.