I have so much stuff its hard to keep track of it all but i do try and upgrade my main rig and gaming rig at least every 2 years with small upgrades in the middle. For gaming rig i try to upgrade video card like every 10-14 months, for the main rig i try and just upgrade mem if needed or proc not much as this machine is usually used for everyday computing.
HTPC:
E4500 Core 2 Duo, Foxconn mATX mobo i had lying around 2GB Ram,Pioneer Bluray Drive,ATI HD2400,250gb HD on a TT Mozart with Vista Ultimate. About 400 bucks since i had the HD mobo and proc i took out of a vostro i upgraded with a E6550 i did OC the e4500 a bit to make bluray smoother so far been runnning for more than ayear and a half and all is stable and running great.
Server: Used to have a older DFI lanparty with a opteron 148 and 5x250gb raid 5 and a 6800 gfx card and windows 2003 all leftover parts from previous builds now replaced with an Aspire h430 home server:$400 extra 2x1TB hd for server $160
Gaming PC:built over 2 yrs ago from scratch. CM690 case with q6600 EVGA780i Mobo, previous 680, 4gb Reaper OCZ ram ddr2, dual 9800gtxSLI now have 260core216 SLI and have next upgrade on stby as have bought i920, and 6gb XMS dominator ddr3 ram in a month or so ill buy an x58 mobo and will keep this for another 18 months minimum. Still have raid0 250gbx2.bout 1000 have pci xfi FAtality
Main rig: Core2 duo e6400ocd, 975x mobo, hd3650, dvdrw , 250gb raid 1 with 500gb and 400gb hd. Lian Li Case
Main rig replacement: Already built still not in service.Core 2 duo 8400 4gb ddr2 TT lanboxlite case with700w modular PS, HD4850 bought for cheap from a friend overkill for nongaming computer proably will replace with 3650 for power savings. 2x750gb raid1 and 1tb drive dvdrw, xfx mATX geforce9300 mobo. bout 600 bucks.
Laptops: Wife has Vaio N series bought in BEst Buy for 500 bucks but now can get better offeres for same or less if we only knew then bought last december. Asus V2s Business laptop for work company bought 1300. Asus A8Js gave to sister bought 2 yrs ago for 1350, Asus eeepc 1000h use for moving around the house and traveling light..450....Macbook core duo bought for 400 bucks used as this was my 1st mac use it for ableton live. Am currently writing this form a MAcbookpro unibody 1800 used for djing and somewhat light usage.
I think that covers mainly everything.Im trying to cut back on spending for the next year as i believe my rigs will be good enough to lat the next 2 yrs except for maybe and video card upgrade along the line for the gaming rig.