+1 for quality parts, with a simple twist. Make small changes each year. I started trying a different approach in 2005. New case, mobo, processor and the like. I got in at a new CPU package design implementation. So I bought the best mobo I could - but the low end CPU. Fast memory - but only 4 gig.
Following year, I added memory at half the price. Following year bought a faster hard drive. Following year the package design was end of lifed, but I got the fastest in the series for 1/3 of the price. Following year a new power supply and new hard drive. Held onto the mobo and core for another 3 years.
Kept the case, fans, hard drive and again bought the best mobo I could. The subsequent purchases followed the same pattern. The leaps in tech each year aren't that great. I bought top end CPU and memory about a year 1/2 later for 1/2 the price. Except for power supplies and Mobos, I improve the system each year for a bit less.