I have seen all the nighttime shows, most multiple times and this is how I rate them:
Fantasmic - I didn't see you mention this one
HEA- Wishes was also in this spot
Rivers of Lights- I like the show. It is peaceful and beautiful but it's just not Disney Stlye.
Illuminations- it's big and impressive but it somehow just lacks than WDW closeness the others have. We had skipped it the last few trip but did it this year using a later in the day FP and it still was a bit blahhh for me.
I really think everyone needs to see every show at least once but this is how I would rate them. We always do a package for Fantasmic, we always just stake out a spot for HEA. I have also seen it from California Gril ( my favorite restaurant on site) and while it is very very cool, I prefer in park viewing. Last trip we did a dining package for ROL but I won't do that again. In the past, we just grabbed a spot anywhere for Iluminations. FP is definitely worth it if it's high on your list to do. Often you can get a 4th or after FP for it.