Based on number of speakers:
* Mandarin Chinese: With over 1 billion speakers, it's the most spoken language in the world, making it incredibly influential.
* English: With around 1.5 billion speakers (including those who speak it as a second language), it's the most widely spoken language globally and is often considered the "lingua franca" for international communication.
* Hindi: Spoken by over 600 million people, primarily in India, it's a major language in a densely populated region.
* Spanish: With over 500 million speakers, it's prevalent in many parts of the Americas, Europe, and Africa.
* Arabic: Over 400 million speakers, primarily in the Middle East and North Africa, make it a significant language in a strategically important region.
Based on cultural influence:
* English: Again, due to its global reach and use in media, technology, business, and education, English has an immense cultural influence.
* French: French is associated with culture, art, fashion, and cuisine, and it's a language of diplomacy and international organizations.
* Spanish: Its influence is vast in music, literature, and cinema, making it a major cultural force.
* Japanese: Its unique culture and its presence in popular media like anime and video games have contributed to its global fame.
Other factors to consider:
* History: Languages like Latin and Sanskrit have historical significance and influence.
* Media: Languages like Korean and Japanese are gaining global attention through their pop culture exports.
* Technology: Many languages have become important in the world of technology, particularly due to their use in software development.
It's important to note that "fame" is a complex concept and different criteria will lead to different lists. Ultimately, the "most famous" languages are those that have the most significant impact on global culture and communication.