Oh, gosh. Depends, there are so many permutations!
OK - I'm older than dirt. I watched the first ep of Star Trek (OS) when it was broadcast, and have loved it ever since. Next Gen is great. Never got into Voyager. DS9 sort of went off into la la land for me after a few years. I enjoyed Enterprise (was a Quantum Leap fan, so Scott Bakula in a Star Trek thingy was a double win). But it seemed to go weird there toward the last, too.
I also (see above, "Dirt: older than") saw the first ever Star Wars when it came out. Enjoyed them immensely for what they were. And love the music. The later released 'installments'? Not so much. And Jar Jar Binks is an abomination to the Universe, IMHO ;-)
Do I *have* to have *one* favorite SF author? ::whimper:: I mean, some of them are really good friends of mine! You expect me to *choose*?! Hmmm...
I enjoy MilSF. And 'Space Opera'. I will not tolerate dystopian defeatism. So, in no particular order whatsoever:
Robert A Heinlein (in a class all his own. Though I didn't go so far as Sarah A Hoyt a give birth to my first born son on his birthday and name him 'Robert Anson'! :-D But I might have if I'd have thought of it!!!)
Tom Kratman
Sarah A Hoyt
John Ringo
Andre Norton (only her early stuff. After Witch World she went really, really woo woo and I am *very* picky about which of hers to read after that)
Edgar Rice Burroughs
Dave Freer
David Weber
David Drake
Terry Prachett
Keith Laumer
Jerry Pournelle
Philip K. Dick
Gordon R. Dickenson
And, in the interests of full disclosure - I *do* beta read for more than one of them who are still, thank God, among us and writing! So, please, don't make me pick *one*! :-)
If she is into SF, she has not yet answered a key question: Star Wars or Star Trek? And her favorite SF author.