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