Craigslist

Its elementary page design has barely changed in 13 years, even as newer, flashier competitors vie for a chunk of the $15 billion online classified market. But so what? Craigslist is a Web pioneer that will never go stale, and remains the essential site for want ads ranging from real estate and used furniture to jobs, romance and one-night stands. Craigslist launched in 100 additional cities this spring, making the site's services available in over 500 cities in 50 countries. To stay ahead of other newcomers with a strong international presence — including Kijiji, Oodle and OLX — the venerable Craigslist now makes its listings available in Spanish, French, Italian and German in some cities. This way, you can't blame the language barrier for fumbling your "missed connection."

—Anita Hamilton