oh yeah - cases, simple is usually better. Lian Li makes solid simple cases. Doors and shit always fail, rattle, squeak. Side panels are good - but usually not filtered for the fans that are on them. So mixed blessing.
Top Fans are a must!! They help keep case temps low, the back fan isnt enough. Powersupply and system heat will pool around your powersupply. PS fans arent meant to cool cases + ps, just PS. So a top exhaust will help a lot.
Antec , Sparkle, and Rosewill make solid powersupplies.
I prefer Asus for intel motherboards, MSI for AMD.
I prefer Intel for handling math processing better (business type apps) + solid performance on games (e6700)
Corsair, Kingston, Mushkin make solid memory. Keep an eye on latency and whats recommended for your board/chip
WD Raptors ok, prefer Seagate for HDD longevity. WD usually only last 3 yrs. Seagates last 6-7. Sata2 is way to go. If price isnt a concern though, you still cant beat SCSI drives. Just loud.
Nvidia still dominating graphics game on the $ per performance segment.
Soundblaster Fatality is a joke. My old Audigy had less issues. More isnt always better in sound segment. Esp if youre going to use junk speakers.
Monitors matter. Whats point of high res card when you have flat blacks and ghosting. My Samsung syncmaster 226bw does well. Great picture. Awesome blacks/greys. I run 2 monitors (Westinghouse for 2nd) on 1 card.
I am not a fan of overclocked graphics cards. My EVGA runs 10% faster than other cards - but at a price - TEMPS. My temps will cook if my ambient temp was above 70. In a room, this will bring up the room temp to 80 in a hurry. I keep my ambient temps about 60.
SLI is a joke if you cant cool them. Hot cards dont run well. And most cases can fit SLI sure, but never enough airflow for 2 monsters running at 140degrees each. If you go SLI, go watercooled