All well-designed logos share these common elements:

• Memorable—they have recall value
• Striking—they grab your attention
• Captivating—they hold your attention
• Educational—you can learn about the company just from seeing the logo
• Simple—it captures the essence of the company’s brand

Nike

Nike’s logo is the most memorable logo in existence. It captures all the important principles of logo design. When you see the swoosh, you instantly think of Nike. Your head is instantly filled with images of sports and the iconic athletes that Nike has sponsored (Michael Jordan, Derek Jeter, Tiger Woods).

Fedex

FedEx’s logo is simple and recognized throughout the world. The bold typeface and contrasting colors leave a lasting impression. Its strongest feature goes unnoticed by many, but is widely admired in design circles. The negative space between the “E” and the “x” forms a bold, forward-pointing arrow. Once you see it, you’ll never look at the logo the same way again.

Lobster.com

It’s a lobster! Dot com. How great is that? Plus, the stylized illustration perfectly represents the brand’s rustic look and feel.

Six Locks

This logo comes from a logo submission site. It’s not for a real company, just a designer’s practice. However, it’s a straightforward, clever design. It’s a good example of type with graphics forming a cohesive design.