Community is regarded as one of the best American sitcoms out there, known for its creative writing from the weird and wonderful mind of Dan Harmon. Community is also known for churning out numerous parodies and homages to film, television, and other pop culture references.

RELATED: Community: 10 Best Episodes, Ranked According To IMDB

For all of its popular and successful episodes, Dan Harmon was not at the helm for Community's fourth season. The fourth season is now known as the "gas leak year." Season four produced most of Community's worst-rated episodes. There have still been episodes from other seasons that haven't met the overall high standards set by Community.

10 Basic RV Repair And Palmistry Sees The Group Go On A Road Trip (7.5)

Community Basic RV Repair & Palmistry

The sixth season of Community is mainly known for its emotional goodbye to the characters and Greendale in its final episode. Not many of season six's episodes are memorable. Basic RV Repair And Palmistry has the group minus Chang in Elroy's RV on a road trip. They need to transfer a giant hand that the Dean purchased to another buyer.

Abed's obsession with cutting to a flashback is a meta that Community is comfortable with using as his ongoing gimmick. However, the execution is a sign that the gimmick is finally becoming stale. Basic RV Repair And Palmistry ends before it really begins.

9 Competitive Wine Tasting Is One Of Season Two's Weakest Episodes (7.5)

Community Pierce Hawthorne Competitive Wine Tasting

In Community's stellar second season, there are very few episodes that aren't considered to be masterful. However, Competitive Wine Tasting is no masterpiece. With Shirley and Annie taking a backseat, Abed has a solo subplot in which he takes down a class by answering "Who's The Boss?" Jeff tries to sabotage Pierce's advances and his relationship with a woman. Troy attempts to exploit Britta's weakness for men showing emotion in their drama class.

RELATED: 10 Community Episodes That Aged Surprisingly Well

Troy and Britta appear to be closer by the end of Competitive Wine Tasting. Jeff starts to regret his hostility towards Pierce. However, Abed doesn't visibly learn a lesson from his actions. Competitive Wine Tasting simply pales in comparison to the rest of the second season.

8 Custody Law And Eastern European Diplomacy Shows The Negatives Of Chang's Chaotic Schemes (7.4)

Community Chang Shirley and Andre, Custody Law and Eastern European Diplomacy

Another episode of Community's second season that isn't as stellar as the rest is Custody Law And Eastern European DiplomacyCustody Law has Annie and Pierce taking a backseat other than the opening scene. Britta dates a questionable guy who is friends with Troy and Abed. Chang tries to prove himself mature to Shirley, in case he is the father to her unborn child.

Chang ends up inadvertently kidnapping two random children, mistaking them for Shirley's boys, in a chaotic move that lands Jeff in jail under false pretenses.

7 Cooperative Escapism In Familial Relations Finally Features A Bad Parody (7.4)

Community Jeff and his Dad in Cooperative Escapism In Familial Relations

Community has had its fair share of episodes dedicated to faith and family, and Cooperative Escapism In Familial Relations sees two different situations play out on Thanksgiving. Jeff has plans with his father, which Britta naturally intrudes on because she wants to interject as a budding therapist. And, Shirley invites the rest of the study group to her house to meet her family.

Cooperative Escapism does shine for letting the audience see Jeff fighting back against his father. However, Shirley's party turns into an attempted Shawshank Redemption parody, which pales in comparison to Community's more successful parodies and homages.

6 Advanced Safety Features Tries To Explore Elroy's Character Further (7.3)

Advanced Safety Features Community Rick and Britta

Season six of Community may well be held in higher regard than the "gas leak year" of the fourth season, but it still had several episodes that suffered. Some episodes failed to recreate the magic of many of the older seasons.

RELATED: Community: 10 Harsh Realities Of Going To Greendale

Advanced Safety Features has the group trying to bond more with Elroy. Jeff struggles with the possibility that someone might not like him. And, Britta's ex-boyfriend "Subway," known now as Rick, returns but is intent on selling cars to the Dean. Advanced Safety Features is fun, but Leroy and Jeff's reconciling talk is short and underwhelming. Advanced Safety Features lacks the closure needed to make it a meaningful episode.

5 History 101 Is The Introduction To The "Gas Leak Year" (7.2)

History 101 Community Annie Britta Troy and Shirley

History 101 kickstarted the fourth season. At its center, History 101 focuses on Abed going to his happy place, which helps him stay in denial as Jeff announces that he is close to graduating and leaving Greendale.

History 101 has Jeff trying to win a contest for seats in a class called "History Of Ice Cream." Britta and Troy go to a fountain, Annie and Shirley try to pull some pranks, and Abed stays within his mind. The subplots link together but none of them are memorable enough for History 101 to be considered a truly strong start of the season.

4 Conventions Of Space And Time Sees The Group At A Convention (7.2)

Conventions Of Space & Time Community Troy and Britta

Conventions Of Space And Time sees the study group go to an Inspector SpaceTime convention. Despite the episode being set away from Greendale, Conventions Of Space And Time still manages to have three separate storylines. Troy and Abed's friendship is tested, Annie pretends to be married to Jeff, and Pierce and Shirley offer feedback on a new version of Inspector SpaceTime.

As is the case in most of the fourth season, Conventions Of Space And Time has no real importance to Community's overall narrative, despite fun cameos from Tricia Helfer and Matt Lucas.

3 Alternative History Of The German Invasion Continues German Stereotypes (7.0)

Alternative History Of The German Invasion Community Shirley Abed Britta and Annie

Alternative History Of The German Invasion does have some entertaining parts but doesn't stand out in Community's episodes. Alternative History features the debut of British actor Malcolm McDowell as Professor Cornwallis and further explores Chang's bizarre reinvention as Kevin.

RELATED: Community: Every Member Of The Study Group, Ranked By Intelligence

However, comparing the study group to Nazis in their disputes with the German trio, albeit with a different leader replacing Nick Kroll's Juergen, makes for an uncomfortable tone. Alternative History also openly mocks German culture and stereotypes. There are still jokes that capture the essence of Community, but Alternative History will always be remembered as insensitive.

2 Intro To Felt Surrogacy Takes A Different Approach With Its Muppets Style (6.8)

Community's Puppet Episode In Intro To Felt Surrogacy In Season 4

Alongside Community's successful parody episodes, the show has explored different visual formats. Intro To Felt Surrogacy starts with the study group feeling embarrassed and awkward. The Dean gives everyone hand puppets, believing that puppet therapy will help them talk about what happened.

Intro To then transitions into the characters being Muppet-like puppets. The writing of Intro To has been criticized, like most of the fourth season of Community. Despite Intro To's problems and issues being resolved quickly through singing and sharing, it still has plenty of heart and reiterates how close the study group are.

1 Economics Of Marine Biology Helps To Humanize Pierce But Does Little Else (6.7)

Community Economics Of Marine Biology Annie and the Dean

Economics Of Marine Biology sees the Dean and Annie aiming to score a "whale" for Greendale by impressing a rich potential student in a tour of the school. However, their plans go overboard. Jeff is tasked with keeping a jealous Pierce busy, which results in the rare occasion where the two get along.

Troy and Shirley have their mini-adventure with them enrolling in a physical education class, which sees them learning how to be PE teachers. All of these subplots are harmless enough, but Abed taking a backseat with a disappointing gimmick is arguably what stops Economics from resonating properly with audiences.

NEXT: Community: 10 Weirdest Classes Offered At Greendale