the world's most famous social media platforms along with their rankings based on user counts

As of my last update in January 2022, here are some of the world's most famous social media platforms along with their rankings based on user counts:

1. Facebook - With over 2.8 billion monthly active users, Facebook continues to be one of the largest social media platforms globally.
2. YouTube - While primarily a video-sharing platform, YouTube also fosters a significant social community, with over 2 billion logged-in monthly users.
3. WhatsApp - Acquired by Facebook, WhatsApp boasts over 2 billion monthly active users, primarily focusing on messaging and voice/video calling.
4. Facebook Messenger - With over 1.3 billion monthly active users, Messenger is Facebook's standalone messaging app.
5. Instagram - Owned by Facebook, Instagram is a photo and video-sharing platform with over 1.2 billion monthly active users.
6. WeChat - Popular in China, WeChat has over 1.2 billion monthly active users, offering messaging, social media, and mobile payment features.
7. TikTok - Rapidly growing in popularity, TikTok has over 1 billion monthly active users, focusing on short-form video content.
8. QQ - Predominantly used in China, QQ has over 800 million monthly active users, offering messaging, gaming, and social networking features.
9. Sina Weibo - Often referred to as China's Twitter, Sina Weibo has over 550 million monthly active users, featuring microblogging and social networking.
10. Snapchat - Popular among younger demographics, Snapchat has over 500 million monthly active users, known for its disappearing messages and multimedia content.

Please note that these figures might have changed since my last update, and there are other social media platforms worth mentioning, but these are among the most prominent ones globally.