What’s Your Preferred CSS Class Naming Convention?

• BEM (Block Element Modifier)
• SMACSS (Scalable and Modular Architecture for CSS)
• OOCSS (Object-Oriented CSS)
• Atomic CSS
• Others

There are various naming conventions for CSS classes, each with its own advantages. What conventions do you use, and why do you prefer them?

Are you more of a dash (-) or underscore (_) person when naming CSS classes?