Depends on what your talking about. Be more specific please.
But to answer your general question, i'll give you some general statements.
Cases-
I love the Antec 300 for the budget range and Coolermaster HAF series for the higher range stuff. Corsair has some good cases but they're quite pricey.
PSU -
Avoid coolermaster at all cost. Their PSU's are mediocre and crap (other than silent m pro units). Corsair and Antec is usually equal in quality since their oems are up there (cwt/delta/ seasonic).