I have 2

1 ) Paparazzi at the 2009 VMA's

http://www.youtube.com/watch?v=2j1Yu42V9oI

I think this was her first performance that really made the world take notice of her, the vocal is her best of 2009 in my opinion.

2 ) Just in 2nd is Marry the night at the 2011 EMA's

http://www.youtube.com/watch?v=vUnVh...eature=related

I think this is just an epic performance, amazing vocal and the choreography at the end is brilliant. I wish she had done this performance on the x factor final at wembley, the song could have been a huge hit with this performance.

Gaga isn't my favourite artist but I absolutely love listening to her sing live. Musically, I think she's the most talented female artist out there right now. My favourite performance of hers is actually an acapella version of Born This Way which she sang in her dressing room. It's floating around on youtube somewhere.

I think that it will always be Paparazzi at the 2009 VMAs.

I am not a fan of hers but I did think her VMA performance of Paparazzi was fantastic, I was not expecting it at all.

Paparazzi at the VMA's
Edge of Glory at BBC Radio 1 Big Weekend
Poker Face/Your Song/Speechless with Elton John at the 2010 Grammy's.

Gaga is not a artist that I have ever liked, from watching the above YouTube videos, she's staying that way.

Terrible

Could you post a few examples of performances you think are good? Perhaps elaborate on why she is "terrible"?

Stunning early vocal performance:

http://www.youtube.com/watch?v=U_hHc7TZjyY

The time where she duetted with a Maria Aragon, it was so sweet but that's also the only time I've seen her sing live.

The You and I performance on Johnathon Ross is one of my favorites.The Telephone/Dance in the Dark Brits performance was pretty good as well.

I've always had a soft spot for these two songs and her very early stuff in general.

This performance of Wonderful from 2006 is really nice - http://www.youtube.com/watch?v=1ZNwsVWVsQw

Paparazzi - VMA 2009
Pokerface - American Idol
Judas - Graham Norton
Hair - Paul O'Grady