i am just wondering an opinion if i should get xbox or PC version
 
Core 2 duo 3.0 ghz
4 gigs of ram
Geforce 275 1 gig of ram on it
windows 7. 
let me know if i need to add more.

Your computer meets the minimum requirements. What I'm wondering (and you too I take it) is if a PC that only meets the min-medium requirements would look better than the 360 version. Because if it only looks good on PC with Crossfire or SLI cards and 8 gigs or ram then what's the point?

Should be more than fine. After playing a bit of it with a comparatively modest rig compared to what people can get these days (SLI 8800GT, AMD 5600+@ 2.8Ghz, 2 GB of RAM on XP) I was able to throw on Very High DX9 settings, which I'm sure look better than the 360 version, without issue.

Im almost similar to that
 
Quad Q9550 3.6ghz (OC)
GTX 275
4gb Ram
WIn7 64 bit
 
Any thoughts on how far i will be able to push Metro?

That PC should run it pretty well. I did some googling for some benchmarks, but the game just came out so there arent any available yet. If you want a more clear picture on how your PC will run the game, wait for the benchmarks.

i got it on steam last night and it runs great! and it looks amazing, it auto-ed my settings to High for some reason so i just left them at that

  @Roqlev said:

" i am just wondering an opinion if i should get xbox or PC version  Core 2 duo 3.0 ghz 4 gigs of ram Geforce 275 1 gig of ram on it windows 7.  let me know if i need to add more. "

@dylanderoo

" @sodiumCyclops: pretty far,  i think but with that 4gigs and quad 3.6ghz you will almost run it perfectly. "