Warning, the following may contain spoilers.
The list spans both the single-player campaign and recently revealed GTA Online mode, and will include objectives such as exploring the game world, securing gold medals in all extracurricular pastimes and hobbies, and modifying weapons and vehicles. A further 11 secret achievements remain under wraps, and are presumably tied to the game's narrative.
The list of alleged achievements is listed below:
Solid Gold, Baby! (50 points) - Earn 70 Gold Medals on Missions and Strangers and Freaks.
Career Criminal (100 points) - Attain 100% Game Completion.
San Andreas Sightseer (30 points) - Explore all of Los Santos and Blaine County.
All's Fare in Love and War (10 points) - Purchase Downtown Cab Co. and complete a private fare.
TP Industries Arms Race (10 points) - Purchase McKenzie Field Hangar and win the arms race.
Multi-Disciplined (30 points) - Attain a gold medal in all applicable hobbies and pastimes.
From Beyond the Stars (15 points) - Collect and return all spaceship parts.
A Mystery, Solved (15 points) - Solve the mystery of Leonora Johnson.
Waste Management (15 points) - Purchase the old dock and collect all nuclear waste.
Red Mist (20 points) - Complete all Rampages.
Show Off (30 points) - Complete all Stunt Jumps.
Kifflom! (30 points) - Complete your path to enlightenment… or not.
Three Man Army (20 points) - Survive 3 minutes on at least a 3 star Wanted Level with all three characters together off mission.
Out of Your Depth (5 points) - You're gonna need a bigger boat…
Altruist Acolyte (5 points) - Deliver an unsuspecting victim to the Altruist Cult.
A Lot of Cheddar (20 points) - Spend a total of $200 million across all three characters.
Trading Pure Alpha (10 points) - Make a profit over your total investments in the stock market.
Pimp My Sidearm (10 points) - Fully mod a weapon.
Wanted: Alive Or Alive (10 points) - Deliver a bail bond target alive.
Los Santos Customs (10 points) - Fully mod a vehicle.
Close Shave (20 points) - Complete all Under the Bridge and Knife Flight challenges.
Off the Plane (5 points) - GTA Online: Complete the Introduction.
Three-Bit Gangster (10 points) - GTA Online: Reach Rank 25.
Making Moves (30 points) - GTA Online: Reach Rank 50.
Above the Law (80 points) - GTA Online: Reach Rank 100.
Numero Uno (20 points) - GTA Online: Obtain first place in all competitive game types.
The Midnight Club (20 points) - GTA Online: Use custom vehicles to win 5 races.
Unnatural Selection (20 points) - GTA Online: Complete all 10 waves of a Survival.
Backseat Driver (10 points) - GTA Online: Direct a driver to 1st place as co-driver in Rally Mode.
Run Like The Wind (20 points) - GTA Online: Survive for a day with a Bounty on your head.
Clean Sweep (10 points) - GTA Online: Finish a Gang Attack without dying and kill at least 10 enemies.
Decorated (50 points) - GTA Online: Earn 30 Platinum Awards.
Stick Up Kid (10 points) - GTA Online: Hold up all 20 Stores.
Enjoy Your Stay (20 points) - GTA Online: Participate in everything Los Santos has to offer.
Crew Cut (5 points) - GTA Online: Complete a Job as a member of a Crew.
Full Refund (10 points) - GTA Online: Kill the thief that mugged you.
Dialling Digits (5 points) - GTA Online: Call for gang backup for the first time.
American Dream (10 points) - GTA Online: Own an Apartment, Garage and an Insured Vehicle.