I don't support hacks, but here are SOME [not all] built-in ones for you.
First thing: You'll need to be either on a server with sv_cheats enabled [easiest way is by devmapping*] or playing a demo.
cg_thirdperson <0/1> Enables thirdperson
cg_thirdpersonshoulderviewmode <0/1/2> Switches to shoulder view mode if in GPP or KoRx. Note that "0" and "1" are identical - a mysterious bug easily fixable.
cg_thirdpersonangle <0/1> Sets angle viewd upon your character horizontally
r_showtris <0/1> Shows all triangles in the world loaded. Basically a wallhack.
r_shownormals <0/1> Shows all vertexes loaded in the world. Similar to above thing.
noclip <0/1> Allows you to fly through the world and through walls.
kill -This is a command. It instant kills you unless cheats is disabled. Hence, it will take 20 seconds [or 5 on some other 1.1 servers] to take action.
give funds <value> gives you credits/frags [evos]
give health -gives health
give stamina -gives stamina
give all -gives all
r_lightmap <0/1> Sets all textures to white ones except animating GIF types. This isn't a cheat in 1.1 apparently.
sv_cheats <0/1> Sets cheats on. Doesn't work in tremulous gpp apparently because its a read-only variable. This can be changed still though by doing devmap <mapname>*.
Other random useful shit:
cvarlist *<part of cvar> Searches for a command variable.
cvarlist <start of cvar> Searches for the start of a cvar.
<cmd/cvar> [press TAB] Autocompletes a cmd or cvar.
r_stereorendering <0/1> Sets 3D mode on. You'll need 3D TV glasses for this.
r_anaglyphmode <0/1> Sets "Spy-kids" style 3D mode on. If you didnt' get it, it's the two-coloured type.
r_showimages <0/1> This is a troll cvar. Sv_cheats doesn't need to be even on to use this.
r_picmip <0-6> Sets picmip value. The higher, the more smudgier textures are. Can be used as a cheap alternative to r_lightmap.
+right;+forward -Run in circles.
cl_yawspeed <value> -Sets the speed which you turn.
sensitivity <value> - Sets mouse sensitivity
+toggleconsole -If you're in gpp or some special 1.1 server where you can exec commands via chat, type this to open console.
3D features are only in tremfusion [maybe TJW's, not sure] and gpp.
Tremfusion is a advance 1.1 client FYI if you didn't know.
