congruous, well-matched, harmonious, miscible, congenial, mixable, agreeable, sympathetic, matched, incompatible, more...

incompatible, conflicting, mismatched, discordant, unsuitable

printer, ink, paper, computer, operating system, software, driver, more...

incentive, brain, pci, ibm, computer, strong, binary, most, least, time

good fit,   get along well,   a good fit,   works well with,   works well together,   a good match,   perfectly matched,   not in conflict,   gets along with,   not conflicting