My favourite plot would have to be Fez at the Foto hut because it has hilarious scenes from the beginning with Kelso's chucker jokes to the end with Fez being fired for doing work instead of goofing off. Leo is also hilarious in this episode with great jokes involving his "boss" and his probation officer ("Things with my probation officer went well. He even wants to see me for some additional years! He's a great guy, man") and Hyde continuously saying "man in his rant was also terrific.
Eric and Donna's non-date was also a good plot with great scenes such as Red being way too involved in Eric's life and Kitty being way too drunk.
Overall, the episode is a very entertaining one, especially Fez at the Fotohut.