Hi. I'll write in this guide about game cheats.
I recommend to not save game with any cheats active, because they blocking achievements !
Hope you'll like it :)

Note: All cheats are activated by dialing cheat's number on your in-game phone

1. GTA IV Cheats - cheats for main game (and for EFLC)
2. GTA IV: The Lost and Dammed - cheats for TLAD
3. GTA IV: The Ballad of Gay Tony - cheats for TBoGT

All cheats will be in format Cheat Number - Description.

Health, Armour and Ammo cheats

- Health, Armour and Ammo.
- Achievements blocked: 'Cleaned The Mean Streets(20G)'.
- Health and Armour.
- Achievements blocked: 'Cleaned The Mean Streets(20G)', 'Finish Him (15G)', 'One Man Army(40G)', and 'Walk Free(50G)'.

Weapons Cheats

- Baseball Bat, Grenades, Combat Pistol, Combat Shotgun, SMG, Carbine Rifle, Combat Sniper, RPG.
- Achievements blocked: 'Cleaned The Mean Streets(20G)'.
- Knife, Molotovs, Pistol, Pump Shotgun, Micro SMG, Assault Rifle, Combat Sniper, RPG.
- Achievements blocked: 'Cleaned The Mean Streets(20G)'.

Wanted Level Cheats

- Remove WL.
- Achievements blocked: 'One Man Army(40G)', and 'Walk Free(50G)'.
- Add 1 WL star.

Vehicles Cheats

- Spawn an Annihilator (Helicopter).
- Spawn a Jetmax (Boat).
- Spawn a NRG-900 (Bike).
- Spawn a Sanchez (Bike).
- Spawn a SuperGT (Car).
- Spawn a Comet (Car).
- Spawn a Turismo (Car).
- Spawn a Cognoscenti (Car).
- Spawn a FBI Buffalo (Police Car).

Other Cheats

- Set random weather from 8 types.
- Gives you the name of song which is now played in game radio

TLaD Cheats...

Vehicle Cheats

- Spawn a Slamvan (Car).
- Spawn a Gang Burrito (Car).
- Spawn an Innovation (Bike).
- Spawn a Double T Custom (Bike).
- Spawn a Hexer (Bike).
- Spawn a Hakuchou Custom (Bike).

Cheats for TBoGT...

Vehicle Cheats

- Spawn an APC (SWAT tank).
- Spawn a BulletGT (Car).
- Spawn a Buzzard (Helicopter).
- Spawn an Akuma (Bike).
- Spawn a Vader (Bike).
- Spawn a Floater (Boat).

Other

- Explosive punches
- Explosive sniper bullets
- Parachute

Hope you'll use it. Sorry for bad English :)

PS: If you have any questions - PM me