Cases - LianLi, Chieftec, Thermaltak
PSUs - OCZ, Antec, Enermax, Fortron, Thermaltake
Monitors - I like ViewSonic, not sure about the others
Motherboards - ASUS, MSI, EPOX, ABIT, DFI, CHAINTEC
CD/DVDs - Lite-On, Plextor
RAM - LOTS of good ones out there: Kingston, Corsair, OCZ, GEIL...