Question: I have been a member of many SE sites for years now, as a result, I am quite familiar with the guidelines and expectations on the platform. However, even after reviewing the help section I can't seem to find much info on this topic.

I saw the topic on jokes (which was answered with ambiguity) but nothing on comments like "thanks for the informative answer" or the like.

I would assume these are likely not a problem but can also see how they might just clutter topics and become excessive.

Is this one of those things where we are supposed to use "common sense"? I hope not, whenever I diverge from a rule-based system I end up in Vegas with 2 $50 hookers.

Answer: 
This is covered in the [Help Center](https://meta.stackexchange.com/help/privileges/comment):

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> ### When shouldn't I comment?
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> 
> Comments are not recommended for any of the following: [...]
> 
> 
> * Compliments which do not add new information ("+1, great answer!"); instead, up-vote it and [pay it forward](https://meta.stackexchange.com/questions/how-to-answer)
> 
> 
> 

Comments like these are liable to be flagged and deleted (usually as "no longer needed"), but the extent to which this happens varies site to site.
There seem to be two different situations you're talking about: jokes in comments and "thank you" comments.

"Thank you" comments or other useless comments that add up to nothing but thanking the poster of a question or answer should be flagged as "no longer needed". These should be expressed in the form of an upvote and/or accept rather than a comment.

Joke comments are a little different depending on the site. Here on MSE, it's okay to have jokes in comments, as long as they don't completely clutter up the comment thread. On Stack Overflow, we don't usually allow a lot of joke comments. Some of them are kept, but many of them are deleted. 

So before you go flagging joke comments, learn your site's policy on what to do with these comments. Don't flag if the consensus is that they're okay.