I play in the resolution of 1028x768, though I plan on getting a new monitor (19") along with a new set up.
I plan on getting the GTX 460 but I don't know if it'll bottleneck with my CPU and if my gameplay will have any huge differences. I don't have the money to afford a GTX 560 Ti so I was wondering what I should upgrade my CPU/Graphics card to.
You're on the right lines in terms of choice considering your system and resolution. Could we know the make and wattage of your power supply unit? This is needed in determining what your system will power.
But for now, initially I will be suggesting an AMD 6850 or a GTX 460.
Your CPU will be a large bottleneck considering it's a dual core, and an old one at that. Whatever modern GPU you get, it's going to be held back in any case.
I can say I've got a similar setup to you man. I've got a GTS 450 with 4gb of ram, and also an Athlon x2 5400+. My 5400 definitely bottlenecks. First thing, if your board supports a quad, grab yourself a quad and soldier on with the 250, you'll probably find it has more life than you think. Also, maybe look for a larger monitor than 19 inch. A few bucks more you can get a 21-22 inch.
dude, your cpu is already a huge bottleneck with the gts250. you will see no benefit from upgrading the graphics card. get a better CPU/motherboard, a new vid card would be a stupid purchase. Upgrade the CPU and you will finally be able to use all the power of your gts250.
As I said, see if you board will take a quad maybe like an Athlon II x4 or Phenom II x4. Drop one of those in, and use your card until you can upgrade. I think you will find you've still got some headroom left in the 250.
^at 1024x768 id say he has an enormous amount of head room. I remember upgrading from an athlon64 to a core 2 duo with my 8800gts (which is slower than a gts250) and noticed an insane amount of improvement at 1440x900.