(Once again, I' going to return to my feature where I describe how I would write my favorite comic book characters in the unlikely event that a publisher allows me near their properties).
Dr. Fate is the quintessential example of a character who was never written as well as when he first showed up. One of the first magic based superheroes, he is today primarily most for having a cool design and being a precursor of Marvel Comics Dr. Strange. As a result, ever since the silve age, there has been an unfortunate tendency to write Dr. Fate exactly like he was on off-brand version of Dr. Strange. (Note that I am talking about the original Dr. Fate. The successors to the mantel were pretty much all off-brand version of Dr. Strange.)
However, reading the original stories it's suprising, how much of a debt the original Dr. Fate stories owed to H.P. Lovecraft. Fate's opponents not only included the traditional evil socerors but mad scientists, tentacled abominations, and Lovecraft's race of Deep Ones. (As Lovecraft's work were still in copyright at this time, they were called something like "Fish Men of Nyarl-Amen"but they were clearly Deep Ones. The new name itself is most likely a reference to Nyarlathotep, yet another of Lovecraft's monstrosities.)
To me, this suggests that the problem with Dr. Fate is not the character. Rather, it is the stories that are told about the character. Modern day Dr. Fate stories simply tend to focus on the superhero aspects of the character, and while those are important, the result is that Dr. Fate come off as something we have seen before.
In my opinion, Dr. Fate works best when there is a strong horror undercurrent to the character. Instead of being retreads of Dr. Strange villains (Fate's archenemy these days is pretty much Baron Mordo with the serial numbers filed off), his villains should be genuinely disturbing and alien. (Strange's villains, while awesome and definitely strange looking, had more in common, behavior wise, with Dr. Doom then Cthulu.) A good Doctor Fate story should do more than be a good superhero story: it should also scare the audience.