Fringe 8 p.m., Channel 25

After five seasons, this sci-fi drama leaves the air with a two-hour finale. I wasn’t a loyal “Fringe” fan; I’ve missed more episodes than I’ve seen. The cast never turned me on. But still, I knew it was a daring and sometimes mind-blowing show that took science to some fascinating extremes. Will Walter Bishop survive? Who will win the final battle against the Observers? Pictured (from left): guest star Michael Kospa as Windmark and Josh Jackson as Peter.