Biased Me wants to say TNG's season 2 because it's my personal all time favorite, but "favorite" doesn't automatically equal "best", so... my vote goes to TNG's season 3.
It's funny, because S2 is generally considered "the best" it seems, but I think an over-abundance of the parallel Earth stories, plus a slight overdose of the lighthearted approach cause me to like 1 and 3 just a little better. But, to your point, it has some of the best individual episodes in the entire franchise.
It’s clear to me after being in this forum for a short time that my views on Star Trek differ greatly to the community at large. The seasons that people adore are mediocre to me while many that people dislike, I enjoyed. I notice this goes for nearly every aspect; including characters, individual episodes, ethics, politics, plot lines, tech etc. I’ve found it quite fascinating. Particular episodes I liked involved Phantasms, Sub Rosa, Thine own self, Genesis and Parallels. I like most of the episodes.
I definitely like Phantasms, Thine Own Self, and Parallells. And I also know what it's like being the fan who doesn't toe the line. I love season 3 of TOS and I love Star Trek V. And I've found staying out of ethics / politics discussions is for the best. I love everyone, but it can be a massive echo-chamber in here on those particular topics, and I've noticed outliers get ganged up on and branded VERY quickly. Welcome to the boards!
Thanks for the welcome. I’m comfortable with having the unique perspectives that I do and can certainly handle myself in terms of mob views and such, especially politically. After all, not being on the political left inspires quite a lot of opposition when in comes to Star Trek. Catch you around the forum quadrant.
TOS Season 1 Shatner, Nimoy and Kelley just eat up every scene; what a way to kick off a franchise! Best technology concepts and designs for a SF show at that time in TV or movie history (yes, better than Forbidden Planet). Season 1 for all the other Trek series come off as weak in comparison.
If it was allowed to merge the best from two seasons that followed each other, answer would be easy. Combining the best 26 episodes from TNG seasons 3 and 4, there's your answer.