The nicest restaurant I've been to is Charlie Trotter's.
Link
Wine Spectator named it the "Best Restaurant in the World" in 1998. It's twice since then been named the best restaurant in the US, and has been on the "Top 50" in the world list multiple times, though it wasn't on the list above.
It was a phenomenal experience, and I'd recommend it to any "foodie" as a bucket list type of place.
Now that I've seen this list, it looks like Alinea may be the place I have our next anniversary dinner.
