Often times I am not interested in the question so much as I am the answer. Unfortunately, the only site option for bookmarking an optimal answer is to bookmark the question. This leaves you having to remember that no the question wasn't that great, but there's an answer in here worth a million. It'd be nice to be able to favorite an answer allowing you to jump immediately to the answer that was much more valuable than the question. I understand that I can bookmark the answers link using my browser but it seems being able to favorite the answer within the site's ecosystem is useful.
Unfortunately, the only site option for bookmarking an optimal answer is to bookmark the question.
There are plenty of easy ways to to bookmark an answer in your browser:
right-click the link item under the question
select "bookmark this link"
If your browser does not have "bookmark" as a right-click option:
right-click the link item under the question
select "open in new tab"
in the new tab, click the bookmark function in your browser (this is usually a little star icon near the address bar)
This isn't possible right now, but I think it would be a great feature. Often the answer you'd like to favorite isn't a great answer to the question, but is something that interests you.
ask.metafilter.com is a great example of a site that functions this way, and it works very well there. Completely unobtrusive, but quite intuitive and very useful.
Please, please, please - I have found some answers which were only tangential to the question but which are something I want to save for later. I use the favorites similar to the way I use the briefcase on SQLServerCentral.com - articles I want to save for later reference for code snippets I might want to add to a library or something.
It seems that I'm becoming less ready to mark a question as "favorite" anymore, because what I really wanted to do was mark an answer as the favorite.
And it can also be the case that up-voting a particular answer doesn't suffice to erase confusion, because you may have up-voted more than one answer under the question.
There probably should be categories for Favorite Answers, Favorite Questions, and Favorite Comments. When you go to your profile and go to Favorites, these lists would be presented in separate views, partly because their data structures would not be identical. For instance, a list of your favorite answers might include the first few lines of the answer.
I'm inclined to believe that by not offering a user the ability to categorize their "favorites" in these sub-categories, it ends up being more work for a person to remember why they made the Question their favorite to begin with (when it wasn't even the question, but an answer or a comment that they really thought was important). It becomes too much mental strain, and so you start asking yourself if it's really worth it to mark any question as a favorite.
This would definitely be a great feature. Nine times out of ten I'm marking a question as a favorite only because I like one of its answers. I often cringe when I do this for a question that I found to be poorly-worded, because it seems to be sending the message that I like the question, which is often not true. I think that Ismail explained this best by saying
One more thing is that favorating [sic] a question for bookmarking a great answer gives badge (reputation) to the asker when the question might not be that great. But the answer is worth a million, so the answerer should be the one who earn reputation
(Badges and reputation and not equivalent, but you get the idea.)
Jeff may have declined this feature in June 2010, but he never gave a reason for doing so. A year later, I definitely think that this proposal would be worth reconsidering (especially given the fact that it has amassed over a hundred votes by now and has been marked as a favorite over 25 times).
It should be noted that the purpose of visitors to the SE sites is to seek answers, not questions. The question asked is merely an impetus to a quality answer. It is the answers that supply the valuable information in the SE network.
I personally enjoy answering other peoples' questions, but I would not be here if the goal of the site was question-focused as opposed to answer-focused. Thus, marking a good answer is more important than marking a good question.
I used to be of the opinion that we should be allowed to mark answers as favorites, but I've since had a chance of heart. The reason for this is subtle, but important.
Until now, I had been conflating Stack Overflow's "Favorite" feature with the Bookmark feature in Mozilla Firefox and Google Chrome. This is understandable and perhaps even natural given the fact that "favorites" in Stack Overflow use the same icon—a star—as bookmarks in Firefox and Chrome. There is a critical distinction in functionality between these, though.
Favorites in Stack Overflow are used to subscribe to notifications of a question's activity (edits and new answers), but bookmarks in Firefox and Chrome are simply used as placeholders for information on the World Wide Web.
In other words, I've been using Stack Overflow's favorites incorrectly.
On further reflection, this does make sense: there's no reason for Stack Overflow to duplicate the functionality of browser bookmarks. Instead, favorites allow you to be notified of updates to a question as if it was your own. This is something that browser bookmarks can not do and is helpful for keeping track of questions other than your own. (Technically speaking, this could also be achieved through RSS feeds, but Jeff has said that he doesn't think RSS has a very interesting or useful future.)
Viewed in this way, it really does seem silly to subscribe to notifications for changes to answers, which have much less activity than the questions themselves. Furthermore, despite the fact that questions are merely the sand that produces the pearl, questions and answers are generally treated as two complementary parts of the whole, and splitting them apart would leave out the "Q" in "Q&A."