I have often debated this with myself but it has to be-

Best-
The Edge of Glory

Worst-
Just Dance

So what are your thoughts?

Teeth wasn't a single?

Best: Bad Romance

Worst: You And I

I'm no huge Gaga fan but I firmly believe that Bad Romance is one of the best pop songs of the last 10 years.

Best: Bad Romance - so instant and great.

Worst: You and I

D to da I.T.T.O!! (spoken with a Kelly Rowland swag)

Best: The Edge of Glory
Worst: Eh Eh (it was released in Australia)

Oh Yeah! Thanks! Mucked up my own thread

Best - You and I (I liked it, looks like I 'am the only one lol)
Worst - Alejandro (ok song but there were better on the Fame Monster and its video just didn't fit the song)

The worst is 'Born This Way', hands down!Cheesy, repetitive and lyrically cliche, it's overall a mess

I think the best is either 'Paparazzi' or 'Love Game', which seems to be quite overlooked but I liked it

(I just realized that it was difficult to respond to this question...Her visuals have overshadowed the music itself so much that I could remember all her videos and rate them, but I couldn't even instantly remember all the songs she's released and their melody )

Best
Paparazzi

Worst
Every other song shes done

Best: Up until now I've always said Paparazzi, but Marry The Night is IMO her best song yet. Utter madness that they've left it this long to release it because it could have been huge.

Worst: Presuming we're talking UK releases only? You + I, love the song but it's not really single material. Outside of the UK 'eh, eh (nothing else i can say)'... It's terrible.

i actually cant even pick, i think Edge Of Glory has passed Bad Romance but Just Dance still is one of my favourites as it changed my life so much!

I dont dislike any songs but Alejandro is her worst to me, not that it is bad. The video ruined the song for me and Dance In The Dark is possibly her best song ever.

Same here. Then again, the vid for TEOG got slated more, yet I still love that song. Weird, isn't it?

Best single - The edge of glory

Worst - Love game

It wasnt horrible though like Alejandro, EOG was only slated because well it wasnt what we were expecting haha it didnt have anything interesting! i dont know what she did in Alejandro but she looked awful, things still arent really the same, im not obsessed as i was and i dont think i ever will be, which is a shame.

Best - Paparazzi

Worst - You and I

I am not a fan, but I know
Worst: Bad Romance by a mile

Best: Bad Romance

Worst: Lovegame

In terms of song quality:

Best: Marry the Night.

Worst: Judas.

In terms of commercial success/ cultural impact:

Best: Bad Romance.

Worst: You and I.

Best: Bad Romance
Worst: LoveGame

BEST TO WORST:

Bad Romance
The Edge of Glory
You and I
Poker Face
Born This Way
Marry The Night
Telephone
Paparazzi
Just Dance
Judas
Alejandro
LoveGame

This is tricky, but I'll give it a go.
Ranked from best to worst:

The Edge of Glory
Bad Romance
Judas
Poker Face
Love Game
Paparazzi
Telephone
Just Dance
Marry The Night
Alejandro
Born This Way
You & I

Best
You And I

Worst
Just Dance

Best: Paparazzi

Worst: You and I