"Good Lovin'" (The Young Rascals)

The Rascals (or "The Young Rascals" as they were known for a few years for legal reasons) pretty much defined the genre of "blue-eyed soul."  The New York-based band had a sound that was equal parts R&B and garage rock, with even a touch of jazz.
Perfect specimen is "Good Lovin' (1966)," which actually is a cover of a 1965 tune by The Olympics, a doo-wop/R&B group best known for novelty songs (like 1958's "Western Movies," which is replete with campy gunshot sound effects).
Story goes, keyboardist/vocalist Felix Cavaliere heard The Olympics' Latin-tinged version on R&B radio in New York and immediately decided that The Rascals had to cover it in their live shows.  
Then, when the band landed its recording contract with Atlantic Records, they cut the song in the studio for their covers-heavy first album, The Young Rascals.  Although the band members weren't too pleased with the results, feeling the final product sounded sloppy, the experts behind the mixing board, producers Tom Dowd and Arif Mardin, convinced them that it had the tight-but-loose sound that would make it an instant hit.  (It went to #1 on the Billboard charts in April 1966.)
Being a keyboardist myself, I always gravitate to Cavaliere's Hammond B-3 solo after the second chorus.  Honestly, there's nothing complicated about it: a few sustained notes over some block chords; he's basically just replaying the horn break from The Olympics' original.  But there's something soul stirring about the resonating, church-y sound he conjures from that electric organ.  It brings to mind jazz organist, Jimmy Smith, who definitely influenced Cavaliere's sound.
And, although it's gimmicky, I still love that false stop at the end of the song, where you get that little bonus reprise of the chorus and Cavaliere sounding like he's having a religious experience.