Here is the full list of all 50 Just Dance Greatest Hits achievements worth 1,000 gamerscore.
Have 4 players on-fire at the same time
Finished a song in the "Songs" menu with at least 4 stars
Finished a song in the "Songs" menu without missing a move
Shouted Out at least once in a song
Finish any song in the "Songs" menu with at least 90% "Perfect" moves
Score 5 stars on 2 songs in a row from the "Songs" menu
Score 5 stars on 6 songs in a row from the "Songs" menu
Score 5 stars on 10 songs in a row from the "Songs" menu
Finish a Duet with 2 players scoring at least 3 stars on both choreographies (2-coach songs)
Finish a Duet with 2 players scoring at least 4 stars on both choreographies (2-coach songs)
Finish any Duet with 2 players scoring 5 stars on both choreographies (songs with 2 coaches)
Score at least 3 stars on every choreography in the "Songs" menu
Score at least 4 stars on every choreography in the "Songs" menu
Score 5 stars on every choreography in the "Songs" menu
Reach 150 Sweat Points with a 3-star rating on any song with Sweat Mode activated
Reach 250 Sweat Points with a 4-star rating on any song with Sweat Mode activated
Reach 350 Sweat Points with a 5-star rating on any song with Sweat Mode activated
Score 3 stars in Simon Says
Score 4 stars in Simon Says
Score 5 stars in Simon Says
Play 50 songs (excluding Just Create)
Play 100 songs (excluding Just Create)
Play 200 songs (excluding Just Create)
Earn 1,000 Sweat Points with Sweat Mode activated
Earn 7,500 Sweat Points with Sweat Mode activated
Earn 15,000 Sweat Points with Sweat Mode activated
Score 5 stars on any song after disabling pictograms in the Settings menu (excluding Just Create)
Score 5 stars on 5 songs in a row with pictograms disabled in Settings menu (excluding Just Create)
Score 5 stars on 10 songs in a row with pictograms disabled in Settings menu (excluding Just Create)
Shout Out at least once in 5 different songs
Shout Out at least once in 10 different songs
Play every song in the "Songs" menu at least once
Score 5 stars on every song while playing the "90's Dance" Playlist in one session
Score 5 stars on every song while playing the "Urban" Playlist in one session
Score 5 stars on every song while playing the "Disco" Playlist in one session
Score 5 stars on every song while playing the "Pop Top 40 (Radio Hits)" Playlist in one session
Score 5 stars on every song while playing the "Oldies but Goodies" Playlist in one session
Score 5 stars on every song while playing the "Warm-up" Playlist in one session
Steal the High Score in the last 10 seconds of a song (Multiplayer/Dance mode)
Score 5 stars in a song while reaching 300 sweat points and earning a sing along star
Successfully perform every golden move on 5 tracks in a row
Score perfectly on every move during a dance off replay
Get every Style once (excluding Just Create)
Get four Dance Styles at the same time! (excluding Just Create)
Dance a song twice during a non-stop shuffle session
Score 5 stars in a medley
Have all 4 players score 5 stars on a song.
Create a choreography in Just Create
Collect 10 choreographies in the gallery
Have 2 players with identical scores in a duet. (Score must be more than 0)