I agree with diverse lifeforms in the universe. Which is why, I suppose, I love Star Trek. The original series. There was so much real science intermingled with fantasy in that series.
A lot more science to back things up these days. Consider how very recently we have discovered incredible lifeforms on our planet...living in the poisonous plumes of underwater volcanic vents. Sulfur based life forms. Life forms that subsist on using the heat to metabolize nutrients poisonous to us.
Theoretical possibilities abound...life forms based on ammonia, silicon, hydrogen flouride, all kinds of wild chemistries found only in the atmospheres of gas giants. Speculation abounds about life on several of the moons around Jupiter and Saturn here in our own system.