Half life 2 is simply one of the greatest shooters ever made, that cant be crossed out.
The most immersive thing about half life 2 is the fact that your not just shooting the same stuff throughout, they have added driving and first person platforming elements to keep you busy.
The story is a little bit generic, set in a sci fi world where an alien race called "the combine" has tooken over city 17 and gordon freeman, a quantam physicist was sent to protect it,the value of the game doesn't lose charm, you might play HL2 a second time to see what you missed, there are some special easter eggs scattered throughout the game.If you get bored of the game, you can play CSS,which is bundled with the game, and if you get bored of that, you have acsess to the games endless mods.
The sound also is a nice touch, they give you stuff that sounds like the real thing,but the audio isn't cutting edge it is still honoroble.
What else can i say about half life 2??? One thing, buy it if you have a pc,the requirements are
Pentium 4 2.4Ghz
Directx 9.0 compatible videocard
Directx 7.0 compatible soundcard
3 GB of free space
high speed internet.
Have fun!!!!!