Good Neighbors by a long shot.
The "bad" episodes from pre movie weren't even bad, they were just weak. Such as Nature Pants, Squeaky Boots, Dumped, Krabby Land and Born Again Krabs. The weakest ones were definitely IWATG and I'm With Stupid but I wouldn't classify them as bad. Even though IWATG is currently my least favorite pre movie episode, it did have a few good moments. Good Neighbors does NOT have any good or enjoyable moments at all. In fact, it would probably be in my top 10 worst episodes if I had one. Squidward gets tortured for no reason and Spongebob and Patrick don't care. You simply cannot compare Good Neighbors to I'm With Stupid. While Patrick was a major prick in that episode, in Good Neighbors, not only Patrick was a prick, but Spongebob was too along with it and Squidward getting tortured is the icing on the cake. I'm even surprised the episode has a 3.7 rating on SBMania. It deserves a 2.5 AT THE VERY LEAST.