Full list of all 55 Grand Theft Auto IV achievements. It takes around 40-50 hours to unlock all of the achievements in the base game on Windows.
The base game contains 40 achievements, and there are 2 DLC packs containing 15 achievements.
Help Billy get his bike back. (The Lost and Damned)
Become leader of The Lost. (The Lost and Damned)
Finish the story. (The Lost and Damned)
In the bike races, whack off 69 bikers with a bat. (The Lost and Damned)
Build Terry and Clay's toughness to 100%. (The Lost and Damned)
Complete all base jumps. (The Ballad of Gay Tony)
Complete the Trinity. (The Ballad of Gay Tony)
Finish the Ballad. (The Ballad of Gay Tony)
Complete 25 drug wars. (The Ballad of Gay Tony)
Win the L.C. Cage Fighters championship. (The Ballad of Gay Tony)
Hit a flag with a golf ball four times. (The Ballad of Gay Tony)
Score 80% or above in all missions. (The Ballad of Gay Tony)
Freefall for the longest possible time. (The Ballad of Gay Tony)
Dance perfectly in both Tony's nightclubs. (The Ballad of Gay Tony)
Score 100% in all missions. (The Ballad of Gay Tony)