2311 Los Robles Avenue- Fun With Flags: Sheldon creates a podcast about flags for vexilology newcomers and experts alike. In various episodes, he is seen filming episodes for the podcast.
- Geology Department: Sheldon frequently likes to speak derogatorily about most other sciences but often points out his complete lack of respect for geology.
- Howard's lack of a doctorate: Howard is the only member of the group without a doctorate, which often leads to disrespectful remarks from Sheldon.
- My Mother Had Me Tested: Whenever asked if he is crazy, Sheldon likes to point out that his mother had him tested as a child.
- Penny leeching on WIFI and food: In many episodes, Penny lets the guys pay for her food and uses their WIFI password for herself.
- Professor Proton: Professor Proton is a childhood hero of Leonard and Sheldon's and is seen in various episodes.
- Sandra Bullock: As his favorite actress, Sandra Bullock is often mentioned by Raj, lovingly called "Sandy B".
- Sheldon's Spot: Sheldon's spot on his couch is sacred to him. No one else may sit on it.
