When I think something is truly good, I say "No way! That is fabulous."
When I am being polite or politely complimentary, I say "That's great." Unless I emphasize the "grrrrr" sound AND the "t" sound ("GrrrreaTTTTT" not so much Tony-the-Tiger as a very mad person with very good enunciation skillz). At that point, you should probably look for an exit.
When I say "Fine," it is most certainly NOT fine. It is merely a substitute for another four letter word that begins with f.
You should tread carefully from that moment on. Think of offering red wine or chocolate. It may be your only hope to get out alive.