It could be funny, serious, happy, sad, philosophical – all manner of emotions and styles.
Occasionally it was quite thought-provoking in the true sense and ultimate purpose of science fiction: "what are the implications of such-and-such, the what if? scenario.
This is explored in episodes such as the third season's Learning Curve, which has just this afternoon been shown (in the latest repeat showings) on Sky One. The premise of this story is a society whose children do all the learning, then pass on that knowledge to the adults via transferable nano-tech 'machines' inside them (nanites).
This is probably the most beautiful of all the SG-1 episodes, particularly in its second half. In the sequence where Colonel Jack O'Neill (Richard Dean Anderson) takes the alien child Merrin on an unauthorised trip off-base, to a school where he is well known, and in just about all that follows, we see a wondrous unfolding of the (in many ways most un-childlike) Merrin – excellently played by Brittney Irvin – and the interplay between her and O'Neill is truly superb television, the acting near-enough perfect with excellent writing and direction too.
Merrin's parting smile just before stepping through the Stargate on her journey back home tells us that O'Neill's ploy has worked, as we see in the final part of the episode. It is a very, very clever twist.
I always find this episode very moving, no matter how many times I watch it; and the brilliance of the 'painting a flower' scene is a particular delight. You can't help but smile! Highly recommended.