Great show but...
There were a few bad episodes, as with every series; good or bad. The ones that weren't that great were Arnold Betrays Iggy, Longest Monday, and New Bully on The Block. I didn't like the ending to Monkeyman but it was hinted that the bullies who beat up Sid got their own payback by Monkeyman himself after he recovered his stolen shoes. That and New Bully on The Block had the worst endings of all the HA! episodes.
And God I hated Wolfgang. That bully was a MONSTER! In one episode, he shows no dignity when Arnold helps him befriend another bully and proceeds to "pound" him and the other 4th graders, sigh. What the hell were you thinking, Craig Bartlett? I wish they would've made an episode where he either got his comeuppance or we find out why he bullies other kids. It worked for Pacifica Northwest in Gravity Falls, why not him? At least it would've made him "somewhat" likable but nope, they don't do anything redeeming with that bastard! At least Torvold showed some respect to Arnold when he tutored him in one episode. Even Big Patty is nice as long as you don't make fun of her. Wolfgang doesn't have a soul. In fact, the only time he was nice was when Arnold's grandpa kicked a football over the entire school when he had to go back to school. Sure he insulted him at first but then he gives him gratitude when he kicks that football. Other than that, he's just a generic one dimensional bully. Seriously Wolfgang was worse than Francis from The Fairly OddParents. He least he got his comeuppance sometimes whenever Timmy used his fairies and they reveal why he bullies Timmy in one episode.