Ray Davies got a couple in one song: L-O-L-A and C-O-L-A.
R-e-s-p-e-c-t and G-l-o-r-i-a were the first ones to pop into my head
H - A - double-R - I - G - A - N, you see,
Spells Harriganuc.
Nat King Cole did a smoking version of “L-O-V-E.” Not sure who wrote it.
And in Clambake, Elvis Presley did maybe the worst song he ever recorded. I don’t know the title, but the song involved Elvis spelling out the word "C-O-N-F-I-D-E-N-C-E. " The problem with this is that “confidence” is a long word, so long that by the time he gets halfway through spelling it out in song, we’ve forgotten half the word and it sounds like he’s just singing a long string of random letters.
I’m a big Elvis fan, and I have to admit that that song (and movie) were terrible.
D-I-V-O-R-C-E, of course.
This shit is bananas. B-A-N-A-N-A-S.
M.I.C.K.E.Y M.O.U.S.E
Does YMCA count? 
S-A T-U-R D-A-Y NIGHT!
S-A T-U-R D-A-Y NIGHT!
S-A T-U-R D-A-Y NIGHT!
I hope that put an earworm into the heads of a few of you. 
Pretty much the whole song: Billy Connolly taking the piss out of Tammy.
The theme tune to British sit-com Some Mothers Do 'Ave 'Em spells out the title in morse code.
What about Tom Lehrer’s thoughts about the subway stops of Boston?
H is for my alma mater Harvard,
C it stands for Central, next stop on the line,
K is for the cozy Kendall station
C is Charles that overlooks the brine…
P is Park Street, busy Boston center,
W is Washington you see…
Put them all together they spell…
HCKC… PW…
Which is just about what Boston means to me!
M is for the million things she gives me
**O ** means only that she’s soft to hold
**T ** for the things she tries to teach me
**H ** is for her heart of purest gold
**E ** for her eyes with love light shining
**R ** means right and right she’ll always be
Put them all together they spell Mother,
A word that means the world to me.
Bloodhound Gang - Foxtrot Uniform Charlie Kilo
Look up the complete lyrics, they’re very “creative”.
“That’s a girlfriend
said G-I-R-L-F-R-E-N
that’s a girlfriend.”
—Jonathan Richman
“R-A-M-O-N-E-S, R-A-M-O-N-E-S, Ramones!”
–The Ramones
Method of modern love ~Hall and Oates (can’t stand that song)
Others that were hits, hmm…
L, is for the way you look at me…
U-G-L-Y! You ain’t got no alibi.
You’re just u-ugly…
–Fishbone
Gimme an F…