Many times I want to tell the person who answers thanks and want them to know I up vote them. In the comment section it says not to so as a comment. Where should I say thanks ?
If you like something, upvote it. That way the respondent gets an increase to their reputation, and posts with more votes float to the top of the page, thereby helping other people recognise that they are more popular (and therefore likely more correct) an answer.
Upvotes benefit everyone.
+1 comments benefit nobody.
I don't want to sift through dozens of
+1 great answer!!! comments to find if there are actually some relevant comments on an answer. And nor does anyone else really.
Telling someone you have voted (and how you have voted) is not necessary. If you want to give your appreciation, just vote for that post and possibly accept that specific answer.
We want to build a Q/A knowledge base here, and everything that distracts from that is removed. Discussions in comments, 'thanks', giving information about your votes, etc., is all unnecessary information that have no value for the overall information shared on the site.
You can point out a specific part of the answer that was helpful if you want to, that will emphasize it for future users which is helpful.