I mainly lurk around here learning all I can from those with much more experience than myself, but we have just returned from an 8 night stay over Mardi Gras week, and might be able to add a bit to this.
We were fortunate enough to have dinner at Artist Point, California Grill, Monsieur Paul, Jiko, Narcoossee's, and Citricos during our stay (also had arrival night dinner at the Grand Floridian Cafe which was surprisingly good but probably not pertinent to this discussion). Some thoughts:
California Grill is certainly not intimate, but the view and dining during the fireworks are amazing. This was by far our favorite restaurant from our last trip 2.5 years ago, and was my birthday dinner this year (I assume coincidentally, we were seated at the same table in the window on the MK end where we had my son's 6th birthday dinner 2.5 years ago which was neat....). I have to say, we were a bit underwhelmed this time around, particularly for the cost. The food was great but not OMG great although some of it may have been our server who was a touch too much. We will go back, but definitely were not as excited about it as before. If a celebratory dinner in a busy place with a high energy level works then it would be great. The view can't be beat.
Monsieur Paul was just incredible. It had probably been 15 years since we last ate there. The menu is somewhat short, but the food is exquisite and the service was just perfect. Only negative is going back to Epcot dressed in what we consider appropriate attire (no shorts and a sports coat or at least button down) so we did it for dinner after a day at another park, returned to villa, unwound, cleaned up, Ubered to the Boardwalk and walked in. Had a wonderful time and fantastic meal although it does not meet the stay on the monorail hotel loop criteria. Fantastic fine dining, negative (or positive depending), it is in a park. You can time dinner right and walk out to Illuminations of course.
Narcoossee's was the disappointment of this trip. Gorgeous restaurant, great location, very average food and service. This was our experience last trip as well. It was fine, but we will probably drop this one from our list next time.
Artist Point. My family all loved Artist Point. It is a little informal and may not really be a special occasion restaurant, but the food was great and it was fun to visit WL. My 9 year old son ate the charcuterie plate at every restaurant that offered one. He declared the one at Artist Point the best, and I cannot disagree. Very very good all around.
Citricos was overall the best meal of this trip for what I would consider true finer dining. The food was phenomenal, and overall it had the most professional service. It is well lit and not very intimate, but just about perfect in every other way. Easily came in first for food and service on this trip. Will definitely go back, and it is definitely appropriate for a special meal/occasion.
But I save the best overall experience for last, although again it may to be the perfect intimate special occasion restaurant for everyone. This was our first time at Jiko and we were all surprised that everyone had the most fun and best food with excellent staff at Jiko. The South African wine flights were very very (surprisingly) good. The food was honestly amazing. Jiko, barring something unexpected on the next visit, has found a permanent place on our dining list. Cannot recommend it highly enough. It came out of no where for us and blew everyone away.
Summary. Best fine dining of our recent trip, Citricos, followed closely by Monsieur Paul. Best overall experience and restaurant I would recommend first to anyone based on our recent visit, Jiko. Loved it.
Reading back over this it is about 4 times longer than I intended and a little schizophrenic, but hope it helps someone. Just my opinions of course. Any questions, let me know. Everyone on wdwmagic, whether they know it or not, has helped immensely with my research, planning and travel now for two WDW trips. I am indebted. Thanks so much. Nice to be able to get a little Disney fix here every day.