Doom is awesome as he's the villain that everyone wants to see because he's just been built up as something awesome. He's like the Earth version of Thanos. Both have taken over their respective areas, both are rightly feared by pretty much anybody who knows about them and if you have them coming after you, you better hope the Avengers/FF/anyone else can protect you from them because nothing else can stop them.
Doom is just a fun character. He's an egomaniac like many supervillains but unlike 99% of them he's done what he's set out to do. Get Respect? Check. Be feared? Check. Rule a country? Check. Take over the world? Check. He even went to the future, retook Latveria then went on to take over the USA and take down the mega corps a few notches before he was done. His 2099 book was one of the few worth reading.
He invented a time machine by himself, has his own country, a nuclear arsenal, built Doombots that are as powerful as he is, is second to Strange as a master magician, fought the devil multiple times, took on everybody who opposed him and either figures out how to win ahead of time or gets enough info thanks to his suit to beat them next time. He's even beat the FF/Avengers/X-Men several times alone when teams of others who were far more powerful could barely hold their own.
He's not really an evil jerkhole like most of the villains are (Norman Osborn) or over confident in his abilities (99% of the rest of them), he just thinks he's right all the time and most of the time he can back it up. He cares for his people and if you hurt them them you're going down no matter what stands in the way.
The only problem I have with how they write him is how they characterize him. Sometimes they'll show him being a caring dictator who cares for his people and lets them live their lives as they would as long as they don't try to revolt. Other times they show him killing one or two just because then siccing Doombots on the rest for no reason.