good :
convenient, appropriate, efficient, suitable, attractive, positive, satisfactory, acceptable, unobjectionable, pleasant.

bad :
incompetent, unpleasant, objectionable, distateful, displeasing, ungratifying.

big :
large, outstanding, huge, important, significant, outsized, gigantic, prominant, tremendous.

small :
tiny, secondary, minor, limited, insignificant, insufficient.

important :
essential, major, significant, serious, crucial, decisive, conclusive, outstanding, determining.

successful :
fruitful, profitable, booming, prospering, prosperous, affluent, productive.