Bart Gets Hit By a Car - S2-E10
Other mistake: When Marge is being questioned, before she says 'If you don't have anything nice to say, then don't say anything at all', there is a shot over her shoulder looking at the blue haired lawyer. Not only is he (the lawyer) there directly in front of her, but he is also sitting on the bench with Burns. In all other shots his chair is empty as it should be.
The Ringer - S1-E1
Continuity mistake: When the Moblins attack Link in his room through a sort of trap door, the hole that is the door keeps changing locations, shapes, and the tiles around it all throughout the fight. Some points even disappearing entirely. (00:01:25 - 00:03:40)
Love 'Em and Leave 'Em - S1-E8
Continuity mistake: After Luigi says "Let's play cupid," he peeks around the corner along with Peach and Toad down at Mario going down the aisle with his "bride-to-be." Luigi, as expected, has been wearing green all episode, but when you see them peeking around the corner, Luigi's hat has become red. In the very next shot showing Luigi from behind, his hat has returned to green. (00:14:40)
Chûgoku kara kita aitsu! Chotto hen!! - S1-E1
Other mistake: When Ranma is battling Genma at the very beginning, she slides into the main road. Behind her is a vending machine for drinks, only, it's marked "DOLINK" (bad transliteration). (00:03:00)