I really liked the first two seasons of Arrow, the first two or three seasons of The Flash, and the first two seasons of Legends of Tomorrow. Though they were all three superhero shows, they each had different tonal qualities. Because the network has had so many superhero shows, I think that suggests the network is very sci-fi friendly.
I haven't seen all of those, but I can agree on Arrow Season One being excellent as well as the first few seasons of The Flash. I didn't get into Legends of Tomorrow because I am not a fan of Time Travel and the like. But early Arrow was fantastic. Plus I felt Dylan Neal was absolutely great as Dr. Ivo and he should have been a series regular. I really enjoy his series The Gourmet Detective, but Ivo was definitely the best performance of his I've ever seen.