Upgraded my PC, but still have old one.
My current PC is based on the GA-MA770-UD3 rev 2.0 M'brd, Phenom 2 X2 550BE and HD4850 Gfx card.
I use it for gaming and as a media centre, including watching/recording HD channels via a VideoMate S350 satellite card.
My previous PC (which I still have, but is now unused) is based on the GA-7N400 Pro2, Athon XP 2500 and AGP GeForce 6600GT.
To play modern games and smoothly watch HD channels such as BBC HD I needed to upgrade.
Also, for storage, the GA-7N400-Pro2 only has 4 IDE channels and 2 SATA 150 ports.
It still works perfectly OK so I think it may be usefull as a file server.
If i remember correctly, I could never manage to get the CPU temp below about 45 C at stock speed with a lapped Thermalright SLK900. I think this was because the CPU socket only had the plastic clips around it so larger heatsinks that screwthough the MB were not compatible.
By comparison my OC'd to 3.7Ghz X2 550BE has never gone above 31 C with a Scythe Mugen 2.
I used my old PC for many years and I expect my current system to last the same if not longer.