seeing some of these songs definitely shows that 'classic' has become devoid of meaning on here

What part (albums) of it exactly?

Doo-Wops & Hooligans - Marry You & Count on Me
Unothodox Jukebox - Treasure

+

As I Am - No One
B'Day - Irreplaceable

Back to Black: Back to Black, Rehab
I Am...Sasha Fierce: Halo, Single Ladies (Put a Ring On It)
21: Rolling In the Deep, Someone Like You
Teenage Dream: Firework

A Rush of Blood to the Head: The Scientist, Clocks
M!ssundaztood: Just Like a Pill
Let Go: Complicated
Fallen: Bring Me to Life, My Immortal
Breakaway: Since U Been Gone, Because of You
PCD: Don't Cha
Loose: Say It Right
Good Girl Gone Bad: Umbrella, Take a Bow
Fearless: Love Story, You Belong With Me
Funhouse: none
One of the Boys: I Kissed a Girl, Hot N Cold
The Fame: Just Dance, Poker Face
The Fame Monster: Bad Romance
The E.N.D.: I Gotta Feeling
Doo-Wops & Hooligan: Just the Way You Are, Grenade, Marry You
Unorthodox Jukebox: Locked Out of Heaven, When I Was Your Man

Take a Bow is a single from the re-issue of GGGB so it can't be included.

Buttons is THE classic.

Get the Party Started, So What, Sober not being classics? How, why?

Didn't include UJ cuz it's from 2012 and that's not that long ago.

If I Were a Boy isn't a classic.

All for You has All for You, Doesn't Really Matter and Someone to Call My Lover and at least two of those are classics.

The fact you haven't added LAMB yet and there are SO many deluded albums/songs in the OP makes me wanna report this for inaccuracy

Maneater? Last Friday Night?

Wtf is My Immortal? Buttons? You Know I'm No Good?

I only consider Hollaback Girl a classic. If more people agree with you I'll add Rich Girl aswell.

My Immortal & Buttons ARE classics. If you don't know them by name, listen to them on Youtube. You Know I'm No Good is discussable.

What is Maneater? We've already established than LFN isn't a classic.

My immortal is one of the best songs of the century

Bitch you TRIED it.

Alejandro is far from a classic, here in Europe, and anywhere else in the world.

Sweet Dreams AND If I Were A Boy are much more iconic than Alejandro. Delusional Stan.

Single Ladies & Halo are big, and have stood the test of time worldwide.

They sound exactly like a timeless pop hit has to sound, there's no "trendy" sound on it.

Breakaway has three. The title track is a classic