3: Help!
Soundtrack to their second movie, this album is oozing with genius. George gets two greatly underrated songs, my favorite of the two being "I Need You." That's the way to describe the whole album: underrated. Aside from the title track, and the most covered song of all time, "Yesterday," people don't really know much from this album. So, go get a copy, it's well worth the money.
2: Revolver
I love every song on this album. It has hits (Like Yellow Submarine and Eleanor Rigby) and some of the most underrated songs of the catalog (Like For No One). This is where they started getting more, *ahem*, creative with the studio techniques. Tomorrow Never Knows and the backwards solo on I'm Only Sleeping are great examples of this. These songs had so much production work that none of them were ever played live by the Beatles as a band.