Yes, there are people who are valued as friends and people who are not. In fact, people sometimes hang out with people they don't even really like. I pay close attention to how my coworkers treat me vs how they treat the others in the group. It is pretty obvious they do not value me as much. In fact, it seems I am mostly ignored when there are others around. And the ones they always seem most interested in talking to are the charismatic guys with the great sense of humor. Girls in particular love funny guys. Just ask girls what they like in a guy and you always see "sense of humor" on their list. I am usually afraid of embarrassing myself, so I end up being the quiet, boring guy. That is probably why I am valued the least, by the females especially.

Also, I disagree with your last comment. Funny is subjective. Not everyone agrees on what is funny and what isn't. Also, nobody is funny 100% of the time. People sometimes say things that are funny and sometimes say things that aren't. Lots of other factors play a role.