As Twitter grows, they stray further and further from just showing you tweets from people you follow, and start showing all sorts of other crap you didn't ask for in your feed, such as "person X liked this tweet" or "here's a tweet from someone you may like", and so on.

There is no "official" way to disable these annoying entries in your feed, but over time people have found secret "tags" that if you put in your mute list, will achieve what you want.

This here is a list of all those available tags. There's no real description of what "kinds" of tweets each block other than the vague name though.