Update: Download link fixed, sorry about that.
Just after I post about the +10, +13 trainers it looks like we have something alltogether way better. PiZZADOX has released the trainer of all trainers (at least for the time being!).
Unzip/Unrar trainer into your game directory, then start trainer with “pztrain.exe”. Start the game using the launch button. During gameplay toggle trainer options by pressing the following key combinations:
Hotkey Option
F6 Toggle Infinite Health
F7 Toggle Infinite Armor
F8 Toggle Infinite Ammo
F9 Toggle Infinite Run
F10 Toggle Infinite Breath
Shift+F6 Toggle Infinite Nitrous
F11 Increase Money
3 No Wanted Level
5 Max Wanted Level
6 Toggle One Hit Kill
7 Toggle Bulletproof Vehicles
8 Toggle One Hit Exploding Vehicles
9 Toggle Freeze Mission Timer
0 Toggle Freeze Game Clock
Shift+3 Get Maximum Muscle
Shift+5 Get Maximum Stamina
Shift+6 Toggle Max/Min Fat
Shift+7 Get Maximum Respect
Shift+8 Get Maximum Gambling Skill
Shift+9 Get Hitman Level on All Weapons
Shift+0 Get 100% Completion
Shift+F7 Get Maximum Lung Capacity
Shift+F8 Get Maximum Bike/Driving/Cycling/Flying Skill
Shift+F9 Get 100 Tags
Shift+F10 Get 50 Oysters
Shift+F11 Get 50 Snapshots
Shift+Del Get 50 Horseshoes
F12 Toggle In-Game Menu*Additional notes about the functionality of these are available in the info file attached to the trainer. Download the trainer now from GTA Garage.