Do you have any parameters? Kids? Need to not be in a park? Have you been before?
For my family of 4, we would do 1900 Park Fare. Crystal Palace we find is much too large and tables much too close together. We find most of the time is spent waiting for characters. The interactions at 1900 are more lovely in my opinion, especially if you wanted to do dinner (which you aren't). It's also been a while since we've been to 1900, so we are due for a repeat visit. We also like this on non-park days to allow us more flexibility and leisure with our day.