All the series have their virtues and their faults. All have shows that are good and shows that are bad. Some I did enjoy, others not so much. I'm not really concerned at all with who is stronger. It's all about heroes to me. I care more that they are strong enough to protect people and defeat whatever force threatens them.
I like having Ultraman there as the ultimate hero of light protecting the future which is something I think even Nexus had though in a different way, Rider as the hero fighting for justice in a darker world, sentai as this bold and bombastic world that shows us that when individuals unite they can be an unstoppable force for good. I'd also love to see the Metal Heroes come back.
Really, I wouldn't want to see ANY of them ever go away yet they could all benefit from an occasional rest. Rider I think needs that the most right now. Sentai could use it to really, but hell will likely have to freeze over twice before that ever happened.