For me the first episode that really resonated with me was Similitude in season 3. That was the first Enterprise episode I ever saw that deserves to be mentioned in the same sentence as other Treks.
It is a shame the show got cancelled right after it finally found some creative footing, it broke out of the stale Berman/Braga mold and became a real Trek prequel.
Seasons 1 and 2 was more, they took the worst aspects of Voyager and combined them with the worst aspects of TNG. without any particularly likable characters or strong performances, or any of the best writers. T'Pol taught villagers to defend themselves from Klingons by ducking to the left, ducking to the right, and then rolling for chrissake. And the Klingons didn't catch on that they were using the same move every time!
Yes, season 4 rules. Probably the best Trek season that is neither TNG nor DS9.