9.5 years ago i did 4 right things when i built my rig:
skipped the Q6600 for a E6750
picked 2GB of DDR2 over 4GB
bought a mature Vista64 instead of XP
Spent money for a 8800GT
Through the course of these last almost 10 years i upgraded my system with mostly second handed components. Now i still play at 1050p with a Q9550@3.8, a R9 270x, 8GB of ram, and an SSD.
I'm particularly glad i saved money and avoided the Q6600, if not: i doubt i would have spent money on a second handed Q9550 a few years later, but Yorkfield was even better than Kentsfield.
Also, after almost 10 years, after 3 GPU, 2 CPU, 3 added HDD\SSD, 8 different dimms, after changing all the caps inside my Syncmaster 2232bw, the most astonishingly thing is that my Enermax Liberty 500 is still going, with everything running overclocked for the past 10 years, without blinking.
My only regret for the Core2 era is to not have tried out to win two bids for specimens of Q6400 and E8700 when i saw those things on Ebay, at a stupidly low price, some years ago.