first type in the console sv_cheats 1
god - God Mode
notarget - Enemies Ignore You
noclip - No Clipping Mode
give <item name> - Get Item
hurtme <number> - Damage Player
impulse 101 - Give All Weapons
impulse 102 - Skulls
impulse 76 - Grunt
impulse 82 - Spawn a Jeep
impulse 83 - Spawn Airboat
buddha - Reduce Health
maps - List Maps
npc_kill - Kill All NPCs in Area
npc_create - Creates an NPC
npc_create_aimed - Creates an NPC aiming away from the player.
hud_quickhelp/text? 1 - Shows crosshair
ch_createairboat - Spawn Airboat
map <name> - Load Specific Map
cl_drawhud 1 - Toggle HUD display On
cl_enablehud 1 - Toggle HUD display On
cl_showfps 1 - Shows FPS Rate
setpos - Move player to specified origin
sv_gravity # - Set Gravity (# = number)
sv_stopspeed # - Set Minimum Stopping Speed on Ground (# = number)
sv_friction # - Set World Friction (# = number)
sv_bounce # - Sets bounce multiplier for physically object collisions (# = number)
sv_maxvelocity # - Sets Maximum Velocity of moving object (# = number)
sv_waterdist # - Set Vertical View when eyes are near water plane. (# = number)
air_density # - Change the density of air. (# = number)