I have been buying cheap power supplies for PCs for years and I have had 4 or 5 fail on me over that time. Last time I bought a power supply unit I decided to pay a bit more and hopefully get a better performance. This did seem to pay off, so when my PSU recently failed on my other PC I did a bit of research and came up with the Toughpower XT.
Previously, I resented paying a lot of money for a component that sits invisibly in the background, but I have since learned that this is money well-spent. The Thermaltake is a modular power supply, so you just use the leads you need and the rest go back in the box, avoiding clutter in the PC. The other thing is that if other components of the PC fail, you could always migrate the power supply across to a new project. My PC has the older Molex (non-SATA) connectors for the hard- and optical-drives, but these were well catered for in the enclosed leads and connectors. The unit seems well-built and was easy to install (or maybe it's just that I have done it so many times . . .!). It is very quiet, and has now been running for a couple of weeks with no problems - but to be fair, even a cheap PSU will be okay at the beginning. One of the reasons I picked this PSU is that my previous one was also Thermaltake and has been running now for over two years with no problems.
One thing I like, is that the fan on the PSU runs on for 30 seconds or so after you power the PC down, cooling the PSU for a while after the power drain ceases. This is designed to prolong the life of the unit. Hard to confirm whether this works at this stage, but the thought has gone into the design and that's what you're paying for.