Some lines are so famous that our brains can complete them after hearing the first two words. Writers and stars of some of the most successful TV shows in history made sure of that. An estimated 93 million Americans watched the finale of Cheers, and tens of millions more grew up with Star Trek and I Love Lucy. How could we not remember the words most often associated with them? There may have been a time when expressions like "Ayyyy," "D’oh!", or "Yabba dabba doo!" made no sense. But these 10 catchphrases have become cultural icons in their own right.