I have a Macintosh IIci that I needed a monitor for and I found the Samsung SyncMaster 731N works because it supports all the different methods of sync (H/V sync, composite sync, & sync on green even) as the ancient Apple CRT it was designed to go with, and it supports 640x480 at 67Hz, so with the Enhance Liberty VGA to Mac Adapter (didn't want to play a guessing game of "will this cheaper adapter work" with a Macintosh IIci that I needed running ASAP for the minimum amount of money spent), and I would hope that since the monitor I recommended is so compatible that you may not need an adapter as fancy as the one I am using, I just didn't want any risk of hassle so I bought the over endowed adapter just in case the Samsung monitor died and I had to use something less compassionate.

It seems weird to see a Macintosh IIci drive a flat screen LCD monitor on built-in video, but it's so satisfying at the same time.