"Cannot run out of time. There is infinite time. You are finite. Zathrus is finite. This... is wrong tool. Never use this."
I think the appeal for me was that underlying story. It was known up front and they could drop the little hints of something building. Even though we couldn't guess where it was going or even which bits were significant, once it arrived we could see where something had come from. For the first time I heard what Kosh said to Sinclair in the pilot episode (when Lyta was scanning his memory of what happened when he got off his ship). "En'til'zah Valen" (excuse my spelling please). Even if I had heard it at the time, it would have been meaningless for years.