The first season of ST:TNG left me and many others wondering who the
heck was driving the series? Thankfully things began to improve after
that. I freely admit that Q was probably my favorite character.

The episode with the being who wiped out an entire species because it
had attacked and destroyed the colony he and his wife were living in (they
killed everyone including his wife, who never who his real nature as a
being just this side of the Q) - his speech explaining what he did and
why was one of the highlights of the series. And Picard declaring that
he couldn't even begin to figure out what to do about such a thing
(the attacking species were apparently rotten SOBs, but of course
that still left plenty of moral ambiguities to deal with. And what do
you do to a being who could obviously make a good chunk of the
galaxy vanish with a thought?).

Could not get into Enterprise. They had such great potential with all
that untapped pre-Kirk/Pike Star Trek universe history but blew it.
Except maybe for the episode with the Mirror Universe.

Deep Space Nine. Felt iffy about it at first, but as the series and
character development grew, I started to like the fact that it wasn't
fully of sqeaky-clean Starfleet types who only listen to classical
music and despise capitalism. And the fact that they were considered
the "underdog" series allowed them to do episodes that might have
been considered too trivial for ST:TNG.

Among my favs: Quark and his family end up back on Earth at Roswell
in 1947 and become the legendary aliens in the crashed ship myth.

I hope some day they will make a series that involves both starships
that cannot go FTL and aliens that are clearly not human actors with
funny noses and ears. We got CGI now - it can be done.