The successor to the Apple II (or at least the one devised in the wake of the Apple III's failure), the Apple IIGS (Graphics & Sound) launched in 1986 and featured power roughly on par with the other 16-bit computers of the time (like the Atari ST and Commodore Amiga) while maintaining backwards compatibility with its 8-bit precursors.
It was impressively popular and a big step forward for the II family, but Apple themselves largely ignored it in favor of the Macintosh before discontinuing the IIGS in December 1992.