Depends on what your talking about. Be more specific please.
But to answer your general question, i'll give you some general statements.
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.
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).
well i m thinkinfg of buying new psu
now i wanna make sure that which brand should i choose
i have 4 choices like cooler master,antec,corsair and thermaltake..what you think is best..my range is 500-600 watt psu
and i have chosen cooler master elite 430 and and cpu cooler :COOLER MASTER Hyper 212 Plus.