I'd honestly say that I can't really pick. A lot of my favorite shows are from vastly different franchises. Super Sentai can generally carry out a story nicely but be boring at times, Kamen Rider can almost always be interesting, but does often drop the ball in terms of story and is a bit too ambitious with its CGI these days, Ultraman is well...CGI absolutely sucks, but is one of the few ways I can enjoy giant action and they generally have great stories.
Takara makes some amazing series that just aren't quite up there in terms of story outside of Ryukendo.