Here is the full list of all 50 Guitar Hero: Smash Hits achievements worth 1,000 gamerscore.
You completed a song in every venue.
You completed a song in a Band (4 players).
You completed a song with all Band members on Expert (4 player Band).
You performed as the Guitarist.
You triggered Star Power simultaneously (4 player Band).
You completed a song with any instrument on any difficulty in local Quickplay or Career.
You completed the Career in a Band (2-4 players).
You got 100% on a song as a Band (4 players).
You scored the highest individual score in a 4 player Band.
You performed as the Bassist.
You completed a song on Expert + (Drums only).
You created a new custom instrument.
You created a new custom Band logo.
You created a new custom rocker.
You performed as the Drummer.
You recovered from a poor performance.
You created a custom tattoo.
You played a song in the Atlantis venue.
You scored 5 stars in a song on Expert with Lars Umlaut in single player.
You won a song with the rock meter in red.
You failed a song with available Star Power in single player.
Get 5 stars on the song Beast And The Harlot as the Drummer on Expert without using Star Power.
You completed the song Through The Fire And Flames with 4 stars or more as the Guitarist on Expert.
You won a Band vs. Band match (8 players).
You completed the Career Tutorial.
You completed single player Expert Career on all instruments.
You hit all Open Strum notes in the song Laid To Rest as the Bassist.
You completed the song YYZ with 5 stars on Expert Bass.
You downloaded a song from GHTunes(SM).
You won 50 online matches.
You played 20 online matches.
You completed all four instrument Careers on any difficulty.
You completed the Career as the Vocalist.
You scored 2,000,000 points on Free Bird as a Band.
You completed the song Smoke On The Water as the Vocalist.
You scored 95% or more on the song Killer Queen as the Vocalist (Expert).
You performed as the Vocalist.
You got a 100 note streak in the song Through The Fire And Flames on Hard or higher as the Drummer.
You completed the Career as the Drummer.
You played 150 songs throughout your entire Career.
You won an online Face-Off match by 25,000 points or more.
You won an online Face-Off match.
You won an online Pro Face-Off match by 25,000 points or more.
You won an online Pro Face-Off match.
You completed the Career as the Bassist.
You completed 100% on any song on Expert in single player.
You completed the Career as the Guitarist.
Complete the song Raining Blood with 5 stars as the Drummer on Expert+.
Perfectly play the Let's Play! section in the song Play With Me as a lead Guitarist on Expert.
Perfectly play the First Blood section of Raining Blood as the Guitarist on Expert.