Here is the full list of all 42 LEGO Star Wars: The Complete Saga achievements worth 1,000 gamerscore.
Shoot First
Crossover: Destroy Anakin with Vader.
Revenge: Destroy The Emperor with Mace Windu.
Revenge: Destroy The Emperor with Kit Fisto.
Crossover: Destroy The Emperor with Darth Maul.
Complete the game to 100%
Collect all available Gold Bricks.
Revenge: Destroy Darth Vader with Obi-Wan.
Crossover: Destroy Jango Fett with Boba Fett.
Revenge: Destroy Darth Maul with Qui-Gon.
Revenge: Destroy Anakin with Dooku.
Get 100 points in Arcade Mode
Destroy 10 characters with one thermal detonator.
Collect all mini-kits.
Collect all available red bricks.
Break Jar Jar 20 times.
Max out the stud counter.
Set off all three Discos.
Unlock all characters.
Finish Episode III in story mode
Finish Episode II in story mode.
Finish Episode I in story mode.
Finish Episode VI in story mode.
Finish Cloud City still wearing a Helmet.
Finish Episode V in story mode.
Perform 20 unblockable combo attacks.
Perform 200 blaster character dodges.
Death Star Trench Run without Firing.
Finish Episode IV in story mode.
Disable 5 Droidikas with R2D2.
Destroy 5 people with one attack (Jedi super slam).
Perform 200 perfect lightsaber deflections.
Ride all mounts types & ride-ons.
Wear Every Hat.
Make 100 Build-its throughout the game.
Pull 25 arms off other characters.
Destroy 300 stormtroopers.
Sell your landspeeder to the Jawas.
Destroy 50 TIE fighters.
Destory 300 droids.
Start a Cantina Fight with 50 casualties.
Play through an entire level online