A recent upgrade has put me from a Thermaltake unrated 850W PSU, some crappy Elite Group Black Edition AM2+ socket mobo, two Patriot Vipers, a AMD Phenom II Black Edition, and 2x Radeon 4770s . I had to replace the PSU, Motherboard, RAM, CPU, and GPU all together - the system had last me a good seven years before a rather terrible death.
In respective order, I upgraded to a Corsair 760 AX Platinum power supply, a Asus Z87 Sabertooth, two Corsair Dominator Platinum, an Intel 4770k at 3.5GHz stock, and a GTX 770 (thanks for the debate on this one Noc, and saving me $).
It was an overall performance surge in terms of parts, and a nice cut out of my wallet, but overall worth it. I needed new parts quite badly. The switch from ATI/AMD to Intel/Nvidia has me sold for now, despite the extra costs - you get what you pay for.