Best album:
Worst album:
Most underrated album:
Most overrated album:
Top 5 best songs:
Top 5 worst songs:
Best video(s):
Worst video(s):
Most creative years:
Most lame years:

Example:

Beyoncé

Best album: '4'
Worst album: 'Dangerously In Love'
Most underrated album: 'I Am... Sasha Fierce'
Most overrated album: 'B'Day'
Top 5 best songs: 'Love on Top', 'Schoolin' Life', 'Hello', 'I Was Here' and 'Countdown'
Top 5 worst songs: 'Video Phone', 'Diva', 'Daddy', Run the World (Girls)' and 'Poison'
Best video(s): 'Run the World (Girls)'
Worst video(s): 'Video Phone (Extended Remix featuring Lady Gaga)'
Most creative years: 2011-2012
Most lame years: 2003-2005

It can be more than 1 artist!

Lady Gaga:

Best Album: The Fame Monster
Worst Album: Born This Way
Most underrated album: The Fame
Most overrated album: Born This Way
Top 5 Best Songs: 'Bad Romace', 'The Edge of Glory', 'Shiza', 'Just Dance', ;Poker Face'
Top 5 Worst songs: 'Black Jesus Amen Fashion', 'Americano', 'You and I', 'Eh, Eh', 'I Like It Rough'
Best Video: 'Bad Romance'
Worst Video: 'Eh Eh'
Most creative 5 years: 2008-2011
Most lame 5 years: 2011- present

I hope she can top the video for 'Bad Romance'!

Gaga
Best album: BTW
Worst album: Cannot pick tbh
Most underrated album: BTW
Most overrated album: TFM
Top 5 best songs: Judas, Scheisse, Boys Boys Boys, Highway Unicorn, Alejandro
Top 5 worst songs: -
Best video(s): Judas, Poker Face
Worst video(s): TEOG
Most creative years: All
Most lame years: 2012

Avril Lavigne

Best Album: Under My Skin
Worst Album: The Best Damn Thing
Most underrated album: Goodbye Lullaby
Most overrated album: She has none
Top 5 Best Songs: 'I'm With You', 'Nobody's Home', 'My Happy Ending', 'Complicated', 'Push'
Top 5 Worst songs: 'Smile', 'Innocence', 'Unwanted', 'Goodbye', 'The Best Damn Thing'
Best Video: 'Nobody's Home' or 'I'm With You' or 'My Happy Ending'
Worst Video: 'The Best Damn Thing'
Most creative 5 years: 2004-2006
Most lame 5 years: 2007-2009

I completely agree on your choices for 'Most Underrated Album' and 'Most Overrated Album'!

Gaga

Best album: Born This Way
Worst album: The Fame
Most underrated album: Born This Way
Most overrated album: -none- (TFM is great, not overrated)
Top 5 best songs: The Edge of Glory, Judas, Bad Romance, You and I, Americano
Top 5 worst songs: Teeth, I Like it Rough, (The only bad ones) Bad Kids, Starstruck, Beautiful Dirty Rich (the basic ones)
Best video(s): Marry The Night
Worst video(s): The Edge of Glory
Most creative years: All tbh
Most lame years: 2012? even then it wasn't lame, just the worst of all of them

Shakira

Best album: Sale El Sol
Worst album: Magia
Most underrated album: Sale El Sol
Most overrated album: Laundry Service
Top 5 best songs: Waka Waka, Addicted to You, Antes de las Seis, Gypsy, Rabiosa
Top 5 worst songs: Tu Boca, Illegal, No Creo, Mariposas
Best video(s): Whenever, Wherever

Lady Gaga:

Best Album: Born This Way
Worst Album: The Fame
Most underrated album: Born This Way
Most overrated album: The Fame Monster
Top 5 Best Songs: The Edge Of Glory, Marry The Night, Heavy Metal Lover, Bad Romance, Paparazzi
Top 5 Worst songs: Starstruck, Highway Unicorn, Electric Chapel, Disco Heaven, Retro Dance Freak
Best Video: Paparazzi
Worst Video: Marry The Night
Most creative 5 years: 2008-12
Most lame 5 years: -

Best album: Blackout
Worst album: ...Baby One More Time
Most underrated album: Circus
Most overrated album: Blackout
Top 5 best songs: Toxic, Everytime, Gimme More, Born To Make You Happy, Slave 4 U
Top 5 worst songs: My Baby, E-mail My Heart, I Will Still Love You, I'll Never Stop Loving You I hate half of ...Baby One More Time
Best video(s): Toxic, Criminal
Worst video(s): Break the Ice, Kill the Lights
Most creative years: 2003-2004
Most lame years: Breakdown years

Why do all the Gaga fans pay dust to You & I. It's her all time best song

Beyoncé
Best album: 4
Worst album: Dangerously In Love
Most underrated album: IASF
Most overrated album: B'Day
Top 5 best songs: End of Time, Schoolin Life, Countdown, Green Light, WDYLM
Top 5 worst songs: Daddy, Signs, Speechless, A Gift From Virgo, That's How You Like It (I don't use any of DiL outside the singles and the title track)
Best video(s): Countdown, RTW.
Worst video(s): Sweet Dreams
Most creative years: 2011-2012
Most lame years:2001-2003.

Best album: Blackout
Worst album: ...Baby One More Time
Most underrated album: In The Zone
Most overrated album: Femme Fatale
Top 5 best songs: I'm A Slave 4 U, Boom Boom Boom, Toxic, Everytime, Boys (Co-Ed Remix).
Top 5 worst songs: anticipating, I love rock n roll, dear diary, email my heart, My Baby
Best video(s): ...Baby, Oops, Slave, Toxic
Worst video(s): Someday, Kill The Lights, Break the Ice
Most creative years: 2002-2007
Most lame years: Femme Fatale Era

Janet Jackson

Best album: janet.
Worst album: Janet Jackson
Most underrated album: janet.
Most overrated album: None
Top 5 best songs: If, That's The Way Love Goes, Escapade, Love Will Never Do (Without You), Nasty
Top 5 worst songs: Anything off her first 2 albums
Best video(s): Nasty, Rhythm Nation, Escapade, If
Worst video(s): Just A Little While
Most creative years: 1989-1998
Most lame years: 1982-84

Best album: Carnival Ride/Blown Away
Worst album: Some Hearts
Most underrated album: Play On
Most overrated album: Some Hearts
Top 5 best songs: Just a Dream, Blown Away, Wasted, Someday When I Stop Loving You, I Know You Won't
Top 5 worst songs: I Ain't in Checotah Anymore, The More Boys I Meet, Look at Me,
Best video(s): Just a Dream, Blown Away, So Small, Before He Cheats
Worst video(s): Undo It, I Told You So
Most creative years: 2005-2010, 2012
Most lame years: 2011

Beyonce

Best album: 4
Worst album: Dangerously In Love
Most underrated album: 4
Most overrated album: B'Day
Top 5 best songs: Love On Top - I Care - Crazy In Love - End Of Time - Countdown - Green Light - Schoolin' Life - Lost Yo Mind (COULDN'T ONLY PICK 5)
Top 5 worst songs: Gift From Virgo - Daddy - The Closer I Get To You - Lay Up Under Me - Summertime
Best video(s): Run The World / Ring The Alarm / Countdown
Worst video(s): Ego
Most creative years: 2011 - 2012 (I'm sure 2013 will be included once we hear 5)
Most lame years: 2010 and this horribly LONG break that we're still in

Taylor Swift

Best album: Taylor Swift
Worst album: Red
Most underrated album: Taylor Swift
Most overrated album: Fearless
Top 5 best songs: Tim Mcgraw, Cold as You, All too well, You're Not Sorry, Enchanted
Top 5 worst songs: Today was a Fairytale, A Perfectly Good Heart, Back to December, the rest are amazing
Best video(s): I Knew You Were Trouble, Begin Again, Tim Mcgraw, Our song, Fifteen
Worst video(s): Back to December, The live videos
Most creative years: 2005-06
Most lame years:

Best album: Back to Basics
Worst album: Christina Aguilera (debut)
Most underrated album: Bionic
Most overrated album: Stripped
Top 5 best songs: Fighter, Keep on Singin' My Song, Monday Morning, Walk Away, Come On Over Baby (All I Want Is You)
Top 5 worst songs: I Hate Boys, Thank You (Dedication to Fans...), Make Over, Sing For Me, Shut Up
Best video(s): Fighter, all of the videos from Back to Basics
Worst video(s): Not Myself Tonight
Most creative years: 2002-2008
Most lame years: 2009-2011

Lady Gaga

Best album: 'Born This Way'
Worst album: 'The Fame'
Most underrated album: 'Born This Way'
Most overrated album: 'The Fame'
Top 5 best songs: 'Dance In the Dark, You & I, Born This Way, Judas'
Top 5 worst songs: 'Eh Eh, Ribbons, Starstruck, Highway Unicorn, Summerboy'
Best video(s): 'Paparazzi, Bad Romance, Telephone'
Worst video(s): 'The Edge of Glory, Just Dance, Marry the Night'
Most creative years: 2009-?
Most lame years: 2008

Best album: In The Zone
Worst album: Circus
Most underrated album: Britney
Most overrated album: None
Top 5 best songs: Shadow, Born To Make You Happy, Lonely, Hold It Against Me, Stronger
Top 5 worst songs: Mmm Papi, My Baby, Guilty, The Beat Goes On, Seal It With A Kiss
Best video(s): Stronger, Baby One More Time
Worst video(s): Break The Ice, Radar
Most creative years: 2003-2004
Most lame years: 2007 or 2010-2011