The GTA V cheats are very interesting. Here they are.

class CCheat
{
public:

	enum eCheat
	{
		POOR_WEAPON_CHEAT = 0,
		ADVANCED_WEAPON_CHEAT,
		HEALTH_CHEAT,
		WANTED_LEVEL_UP_CHEAT,
		WANTED_LEVEL_DOWN_CHEAT,
		MONEY_UP_CHEAT,
		CHANGE_WEATHER_CHEAT,
		ANNIHILATOR_CHEAT,
		NRG900_CHEAT,
		FBI_CHEAT,
		JETMAX_CHEAT,
		COMET_CHEAT,
		TURISMO_CHEAT,
		COGNOSCENTI_CHEAT,
		SUPERGT_CHEAT,
		SANCHEZ_CHEAT,
//		SLOWNESS_TEST_CHEAT,
		NUM_CHEATS
	};

	
	// ** HOW TO ADD A NEW CHEAT **
	// 1) add a new enum above for the new cheat, and updated the enum of cheats ids in commands_misc.sch
	// 2) if it requires a function, create one and add it to m_aCheatFunctions, otherwise just add a NULL in the right place
	// 3) add a corresponding entry to m_aCheatNameIds, which is the number of the cheat id held in american.txt which is displayed when the cheat is activated
	// 4) add the pad/keyboard string to activate the cheat into m_aCheatStrings
	// 5) run the game in release / debug, and activate widget 'Game Logic/Cheat/Output file cheat hashkeys  this will generate the CHEATHASHKEYS.DAT file
	// 6) copy the contents of this file and paste into m_aCheatHashKeys
	// 7) build and run the game again and the cheat should work
	
	// ** HOW TO TEST IF A CHEAT IS ACTIVE ** 
	// call IsCheatActive() with one of the enums above

	// Stick a few cheats on the keyboard to help when debugging
#if !__FINAL
	if (m_bAllowDevelopmentCheats)
	{
		if (CControlMgr::GetKeyboard().GetKeyJustDown(KEY_H, KEYBOARD_MODE_DEBUG, "health cheat"))
		{
			HealthCheat();
			cheatDisplayf("H - Health restored!");
		}
		if (CControlMgr::GetKeyboard().GetKeyJustDown(KEY_W, KEYBOARD_MODE_DEBUG, "weapon cheat") 
			REPLAY_ONLY( || CControlMgr::GetKeyboard().GetKeyJustDown(KEY_W, KEYBOARD_MODE_REPLAY, "weapon cheat")))
		{
			WeaponCheat1();
			cheatDisplayf("W - Weapons!");
		}
		if (CControlMgr::GetKeyboard().GetKeyJustDown(KEY_V, KEYBOARD_MODE_DEBUG, "invincibility cheat"))
		{
			CPlayerInfo::ms_bDebugPlayerInvincibleRestoreHealth = false;
			CPlayerInfo::ms_bDebugPlayerInvincible = !CPlayerInfo::ms_bDebugPlayerInvincible;
			if (CPlayerInfo::ms_bDebugPlayerInvincible)
			{
				char *pString = TheText.Get("HELP_INVIN");
				CGameStreamMgr::GetGameStream()->PostTicker( pString, false );
				cheatDisplayf("V - Invincible activated!");
			}
			else
			{
				char *pString = TheText.Get("HELP_NOINVIN");
				CGameStreamMgr::GetGameStream()->PostTicker( pString, false );
				cheatDisplayf("V - Invincible deactivated!");
			}

			if (NetworkInterface::IsGameInProgress())
				GetEventScriptNetworkGroup()->Add(CEventNetworkCheatTriggered(CEventNetworkCheatTriggered::CHEAT_INVINCIBLE));
		}
		if(CControlMgr::GetKeyboard().GetKeyJustDown(KEY_V, KEYBOARD_MODE_DEBUG_ALT, "invincibility cheat restore health"))
		{
			CPlayerInfo::ms_bDebugPlayerInvincible = false;
			CPlayerInfo::ms_bDebugPlayerInvincibleRestoreHealth = !CPlayerInfo::ms_bDebugPlayerInvincibleRestoreHealth;
			if (CPlayerInfo::ms_bDebugPlayerInvincibleRestoreHealth)
			{
				char *pString = TheText.Get("HELP_INVIN_R");
				CGameStreamMgr::GetGameStream()->PostTicker( pString, false );
				cheatDisplayf("Alt-V - Invincible + restore health activated!");
			}
			else
			{
				char *pString = TheText.Get("HELP_NOINVIN_R");
				CGameStreamMgr::GetGameStream()->PostTicker( pString, false );
				cheatDisplayf("Alt-V - Invincible + restore health deactivated!");
			}

			if (NetworkInterface::IsGameInProgress())
				GetEventScriptNetworkGroup()->Add(CEventNetworkCheatTriggered(CEventNetworkCheatTriggered::CHEAT_INVINCIBLE));
		}
		if(CControlMgr::GetKeyboard().GetKeyJustDown(KEY_V, KEYBOARD_MODE_DEBUG_SHIFT_ALT, "invincibility cheat restore armor with health"))
		{
			CPlayerInfo::ms_bDebugPlayerInvincibleRestoreArmorWithHealth = !CPlayerInfo::ms_bDebugPlayerInvincibleRestoreArmorWithHealth;
			
			char *pString = CPlayerInfo::ms_bDebugPlayerInvincibleRestoreArmorWithHealth ? TheText.Get("HELP_INV_A_ON") : TheText.Get("HELP_INV_A_OFF");
			CGameStreamMgr::GetGameStream()->PostTicker( pString, false );
			cheatDisplayf("Shift-Alt-V - Invincible + Restore Health switched modes!");
		}
		if(CControlMgr::GetKeyboard().GetKeyJustDown(KEY_W, KEYBOARD_MODE_DEBUG_CTRL, "Infinite Ammo"))
		{
			
			static int AmmoLimit = 0;
			AmmoLimit = (AmmoLimit + 1) % (2 + __BANK);
			CPed* pPlayer = CGameWorld::FindLocalPlayer();
			if (pPlayer)
			{
				if (pPlayer && pPlayer->GetInventory())
				{
					const bool shouldUseInfiniteAmmo = (AmmoLimit == 1);
					pPlayer->GetInventory()->GetAmmoRepository().SetUsingInfiniteAmmo(shouldUseInfiniteAmmo);
#if __BANK
					const bool shouldUseInfiniteClips = (AmmoLimit == 2);
					pPlayer->GetInventory()->GetAmmoRepository().SetUsingInfiniteClips(shouldUseInfiniteClips);
#endif
				}

				//Display confirmation debug text (if the HUD is enabled.)
				static const char* s_Strings[3] = {"HELP_AMMO", "HELP_AMMO_UNL", "HELP_AMMO_UNLCL"};
				char *pString = TheText.Get(s_Strings[AmmoLimit]);
				CGameStreamMgr::GetGameStream()->PostTicker( pString, false );

				cheatDisplayf("Ctrl-W - Activated: %s", TheText.Get(s_Strings[AmmoLimit]) );
			}
		}
#if __BANK && 0	// Disable this since script uses S for skipping missions so can accidently force a slow zone
		if (CControlMgr::GetKeyboard().GetKeyJustDown(KEY_S, KEYBOARD_MODE_DEBUG, "slowness cheat"))
		{
			CVehicle::ms_bForceSlowZone = !CVehicle::ms_bForceSlowZone;
		}
#endif
		if (CControlMgr::GetKeyboard().GetKeyJustDown(KEY_F3, KEYBOARD_MODE_DEBUG, "decrease wanted level"))
		{
			CCheat::WantedLevelDownCheat();
		}
		if (CControlMgr::GetKeyboard().GetKeyJustDown(KEY_F4, KEYBOARD_MODE_DEBUG, "increase wanted level"))
		{
			CCheat::WantedLevelUpCheat();
		}
	}
#endif //!__FINAL

void CCheat::HealthCheat()
{
	// Disable the health check when injured, it doens't correctly revive the player
	if( FindPlayerPed() == NULL || FindPlayerPed()->IsInjured() )
	{
		return;
	}
	cheatDisplayf("HEALTH UP");
	
	IncrementTimesCheatedStat();

	FindPlayerPed()->SetHealth( FindPlayerPed()->GetPlayerInfo()->MaxHealth );
	FindPlayerPed()->SetArmour( FindPlayerPed()->GetPlayerInfo()->MaxArmour );
	FindPlayerPed()->ClearDamageAndScars();

	// Fix car
	if (FindPlayerVehicle())
	{
		if(!FindPlayerVehicle()->IsNetworkClone())
		{
			if(FindPlayerVehicle()->GetStatus() != STATUS_WRECKED)
			{	
				FindPlayerVehicle()->SetHealth(1000.0f);
				FindPlayerVehicle()->Fix();
			}
		}
	}
	CNetworkTelemetry::CheatApplied("H");

	m_LastTimeCheatUsed[HEALTH_CHEAT] = fwTimer::GetTimeInMilliseconds();
	SetCheatActivatedMessage(HEALTH_CHEAT);

	if (NetworkInterface::IsGameInProgress())
		GetEventScriptNetworkGroup()->Add(CEventNetworkCheatTriggered(CEventNetworkCheatTriggered::CHEAT_HEALTH));
};