Green With Evil (1): Out of Control - S1-E17
Continuity mistake: Up until Green No More in Series 2 (where the Green Ranger powers are destroyed), the Green Ranger's overshield constantly changes between solid-looking metal to flimsy-looking cotton. This is the most obvious difference between the Japanese and US footage.
Fortune Cookie / Dear John - S3-E8
Continuity mistake: When Filburt first reads his fortune cookie, it says "Bad luck and misfortune will infest your pathetic soul for all eternity". But later on when he is walking down the street it says "Bad luck and extreme misfortune will infest your pathetic soul for all eternity". (00:03:25 - 00:04:25)
When Two Worlds Collide - S5-E3
Continuity mistake: Gary has to feel around in mid air for the portal as the wall has just been bombed. But when he reaches through, later, his arm comes out of the wall which has somehow returned.