Some notable examples of poor GUI design include:

1. Microsoft Bob (1995): Overly complex and cluttered interface, attempting to simulate a virtual assistant.

Lesson: Simplicity and clarity are essential in GUI design.

2. Windows 8 (2012): Confusing blend of desktop and tablet interfaces, with a steep learning curve.

Lesson: Consistency and intuitiveness are crucial in GUI design.

3. Apple's iTunes (2001-2019): Overly complex and feature-bloated interface, making it difficult to navigate.

Lesson: Focus on core functionality and simplify features.

4. Google+: Confusing navigation and inconsistent design language.

Lesson: Establish a clear design language and intuitive navigation.

5. Facebook's Timeline (2011): Initially confusing and cluttered interface, overwhelming users with information.

Lesson: Gradually introduce new features and prioritize clarity.

6. Microsoft's Clippy (1996-2007): Annoying and intrusive virtual assistant, disrupting workflow.

Lesson: Avoid interruptive and annoying features.

7. Palm OS (1996-2009): Inconsistent and cluttered interface, with poor typography.

Lesson: Establish a clear typography and visual hierarchy.

8. Yahoo!'s Homepage (2000s): Cluttered and overwhelming interface, with too many features.

Lesson: Prioritize simplicity and focus on core functionality.

These examples demonstrate the importance of:

- Simplicity and clarity

- Consistency and intuitiveness

- Focus on core functionality

- Gradual introduction of new features

- Avoiding interruptive and annoying features

- Establishing a clear design language and visual hierarchy

By learning from these examples, designers can create more effective and user-friendly GUIs.