What are must have game for x-box?
 

I know Halo is one of them
What else?

Spliter Cell: Pandora Tomarrow

Soul Calibur 2, and Knights of the old republic if you like Starwars, and RPG's.

ninja gaiden and star wars: nights of the old republic

Check Top Spin if you liked games like Virtua Tennis.

Just bought Splionter Cell, it is definately one of the greats.

FIFA 2004 and NBA Live 2004 It's good game in sport!

My list
 

I think this is a completely pointless thread, since everyone has different tastes in games and what one person says is good is not necessarily what another person will think.

Still, it gives me an excuse to list games that I like. I've put the games under 3 sections - ones that are best only for single player, ones best for multiplayer, and those that are good single AND multiplayer (no particular order):

Single Player only:
-----------------------------------
GTA3/Vice City
Ninja Gaiden
Sonic Heroes


Multiplayer only:
-----------------------------------
Soul Calibur 2
Project Gotham 2
Worms 3D
Capcom Vs SNK 2


Both:
-----------------------------------
Splinter Cell 2 (system link / xbox live for multplayer only)
Halo



(Halo, Soul Calibur 2, Project Gotham 2 and GTA3 are the games I've played most.)

Dead or Alive: Beach Volleyball ... *drool*