If you're going to get Stellaris it's probably wise to get Utopia and Apocalypse with it.
Noted. My nephew has been trying to get me to play for about a year. I'm finally getting into the frame of mind that I think I could enjoy it. (Sometimes, I play a genre of game completely out of my system. Like the time I played about 6 campaigns of Warhammer Total War in a row, and then my nephew asked if I wanted to try this game called "Stellaris".)
I like Stellaris, but it's not as compelling to play as some other games. Don't get me wrong, it's fun (assuming you're into 4X type games) but rarely does it leave me going to bed planning what I'll do next.
I tried the Master of Orion remake, but it's not the same feeling as MoO2. When it comes to space 4x, MoO2 was my mostest favoritestest. Stellaris looks like it could be fun enough, though!