tmdgm24, you've gotten a lot of good advice from some very smart people. I agree with almost everything said above.
I have a few things to add:
- With an old CRT monitor, games are going to be much easier to drive than with a modern monitor due to the lower resolution. Meaning less graphics potency required.
- When you do upgrade your monitor, aim for something that is listed as 1080p or 1920x1080 (they mean the same thing). Anything lower is subpar, anything higher will be needlessly expensive and much more difficult for your graphics card to drive. Expect basic models to cost $130-160 depending on the size you buy (21.5" - 24").
- JustAnEngineer is a great guy and a tribute to this website and this thread, but he's exaggerating the performance difference between the R7 265 and the GTX 750 Ti. The 750 Ti is almost as good according to the TR benchmarks. The difference is maybe 7-8%, or only a few frames per second when it matters.
- One advantage of the 750 Ti is that it doesn't require a PCIe power connector that you almost certainly don't have. The AMD competitors and anything bigger will require you to replace your power supply.
- Another advantage of the 750 Ti is that the minimum recommendations for power supplies are a mere 300 watts according to Scott Wasson himself. Everything else requires more.
- If you choose to wait: even if Nvidia doesn't replace the 750 Ti directly right away, new cards with better performance push down the price of all cards. So the next generation out in a month or two can only help your situation regarding purchasing power.
If you choose you want a bit better performance and want a bigger card, your current power supply is sure to limit you, case space likely will limit you, and cooling (and therefore noise) will also be an issue. Getting a 750 Ti is cheap and easy. Getting something bigger is a lot bigger headache.
But the good news is that the 750 Ti gets 44 frames per second in Tomb Raider (2013) on "Ultra" at 1080p, and more if you set it down to "High". (Which is better, smoothness or eye-candy, depends on your preferences.) This is good enough for any attentive gamer that isn't a true enthusiast. But enthusiasts aren't going to be using stock builds from HP: they're going to be using custom built or boutique manufactured PC's that cost a lot more, with monitors higher res than 1080p. In short, you're in a prime position to get good bang for your buck, but if you want more, you're going to have to replace a lot or start from scratch (a wonderful project if you have the time, money, and interest).
My advice: get the 750 Ti now, or wait until Big Maxwell is out in a couple of months, at which point you buy the 750 Ti or equivalent.
Let us know what you decide and how it turns out!