Whenever I read an article on what an act's best song are, I've noticed that it's very rarely the band/singer's most popular. It's something I noticed on here as well. Whenever there is a thread about such a thing, the act's fans will say it's a song that most people wouldn't know.

Now, I'm not disagreeing with them, they're probably right but it's something I've always wondered. If you are a properly huge fan of an artist or group, is what is considered their biggest hit what you think is their best hit. And what band's best song were actually their most popular. And how come their best single wasn't as successful as their biggest hit?

There's no right or wrong when it what is 'best', it's all subjective.

Individual band members will often have different favourites, just as their fans will, although it will often be the case the most fans favourite will be the biggest hit as more of them bought it. Although that may not always be true as many artists biggest hits also appeal to those who may not necessarily consider themselves as fans of that artist, they just happen to like that particular track.

That's the idea of a single though, to promote an album and sell, the most commercially pleasing song. You would probably find most fans and even the artists themselves favourite songs have never had a single release and are just album tracks.

Best song indicates the singles and the singles success all depends on time/place. How much hype and attention an act is getting? Are they at their peak in terms of attention/press? Is there a promotional tie in charity record/movie/Christmas record?
There are tons of reasons for a singles success and more often than not it has nothing to do with music itself.

It's easier to tell which song is the best by an act years down the line and seeing which tracks have longevity and in most cases it's not the track that's sold the most. That song usually shows when the act was at the height of their popularity in most cases rather than creatively.