Which graphics card is the best upgrade for this older 1080p gaming PC?

A GTX 1650 is less demanding on the power supply, but it is also noticeably slower. It makes sense only if your 450 W unit is low quality or lacks the proper PCIe power connector. Otherwise, the 1660 Super offers considerably better 1080p performance.

An RTX 3050 could also work as a final graphics-card upgrade, especially if you want newer features and more VRAM. However, it usually is not good value compared with a 1660 Super or similar AMD card. The older processor will still limit performance in games such as CS2 and Call of Duty.

It is also worth checking comparable AMD cards. They can sometimes deliver better performance for the money, especially when the system is limited by the CPU. Just verify the card's power requirements, case clearance, and the age and quality of the power supply before buying.

The GTX 1660 Super is probably the best-balanced choice from your list. It is much faster than the GTX 1650 and should work reasonably well with a 450 W supply, assuming the power supply is decent and has the required PCIe connector. Your i7-3770 will bottleneck it in some CPU-heavy games, but the card should still provide a major improvement over the GT 730.

I would avoid spending much on this platform. The processor and DDR3 memory are already quite old, so saving for a newer system—such as an affordable AM4 build—would give you a much larger improvement overall. If you need an upgrade immediately, choose a reasonably priced midrange card and plan to replace the rest later.