Haha, I've been blessed (or perhaps cursed) to see NiGHTS before. There are a few instances in which I'm comfortable sharing while the others... Ehh.
The first instance I was in a floating candyland. I'm not joking. There was a purple brick path that swirled around in an almost insane fashion, and the sky was pink and purple and filled with clouds that held lollipops and teddy bears. From the doors (I assumed at the time it was a sort of nightopia? It had the doors from JoD in it after all.) to the end of the pathway was nothing but pinks, purples, and sugar-infested sweets. At the end of the pathway, there was a black winding staircase, that extended beyond my view into the clouds above, however broke off a few feet under the pathway. Below everything was a sea of black sludge. NiGHTS appeared behind me, and we talked for a little while about the place I was in and what I was supposed to do. At the time, he believed it was my nightopia, and that the winding staircase was my pathway to paradise; writing my first novel. At the end of the dream, I was climbing up the stairs.
The second instance was a very brief encounter during some sort of zombie dream; in the dream, someone had used a spell to summon a zombie that would kill anyone it came in contact with, so I was running away from it. After distracting it, I ran into an arcade where I met up with some "friends" (People I didn't know in real life but were apparently my friends in the dream) And then, I turned to see NiGHTS on one of those car-racing arcade games. He looked at me and smiled, gave me a wave before asking me "Having fun?" Before I could process that I was dreaming, however, I was dragged away by my friends.
The third instance was when I was dreaming about school; I was visiting since I've graduated, and for some reason one of the teachers thought I was her student and I was skipping class. After a moment, I realized; "Wait a second. Something isn't right here." And when I realized I was dreaming, I changed everything; it went from being a school to being a greek temple of some sort. That is when NiGHTS appeared, and he scolded me for using my lucidity to change the dream. He was pretty miffed that I was even lucid at all. In the end, he tricked me into thinking I had woken up to stabilize my lucidity and make me unaware I was still dreaming.
I've seen Reala before as well; though only once or twice. He appeared in the candyland area and was conjuring walls made out of sour memories to stop me from climbing the stairs.
I've also had one dream that was about me making a movie related to NiGHTS and there was a bunch of merchandise for the movie being sold and I wanted all of the things.
Those are all the instances I'm comfortable sharing.