These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Award Snub: Nominated eleven times for the Best Metal Performance Grammy, eleven times denied.
Awesome Music: Start with Killing Is My Business... and go from there.
Friedman's lived in Tokyo since 2003, speaks fluent Japanese, plays for J-pop singers (among others) and hosts two metal-themed TV shows. Quite busy.
If you regard Dave as badass in the first place, his decline from "snarky but sociopolitically aware metal musician" to "racist, homophobic, bigoted, Conspiracy Theorist loudmouthed asshole" is very unnerving to witness.
Critical Dissonance: Cryptic Writings was hailed by many critics as the band's best album since Rust In Peace but garnered a mixed reception from fans, who saw the album as a further attempt at pandering to the mainstream. The album has been better received since the band started using those sorts of pop choruses in heavy songs (such as Never Walk Alone and 44 Minutess).
Dork Age: As said before, the period between Cryptic Writings until the band's reunion and The System Has Failed.
The end of Megadeth's most acclaimed period is Cryptic Writings, and people might stop there. Some people add The World Needs A Hero, but it has mostly been forgotten due to poor promotion. More still will add the post-2004 albums (The System Has Failed and onwards). The only general consensus is that Risk is the "worst" (read: least metal) of the thirteen albums, and many fans would rather it hadn't been released.
Or, if an album doesn't have ellipses in either the title or a song within it, it isn't canon. This of course means everything between Rust In Peace and The World Needs A Hero doesn't exist, so make of that what you will.
Mis-blamed: While people blame Executive Meddling for what became Risk, Dave has admitted in interviews that he's as much to blame for it as anyone else. As mentioned above, Cryptic Writings got the band increased mainstream attention (though not increased album sales), and Dave effectively decided "Hey outside songwriters! This mainstream attention thing is pretty cool....let's have some more of that please!" He also stated in his autobiography that Marty Friedman was getting tired of metal and itching to move to other styles, and some of the musical changes were done to appease him and keep him around long enough to complete the album. The result...was not quite what he (or anyone else) wanted.
Regarding Mustaine remixing and remastering all of the albums from Killing Is My Business... through Risk while he was recovering from the arm injury. While they have cleaner production, insightful liner notes, lots of pictures, and plenty of bonus tracks, the changes can be a bit disquieting from the originals. Generally, people will agree that the remasters of Killing Is My Business... and So Far, So Good...So What! improved those albums tremendously. Opinions are more sharply divided about the other albums, and the remaster of Rust In Peace suffers a bit because the master vocal tracks for "Take No Prisoners", "Five Magicks", "Lucretia", and "Rust in Peace...Polaris" were lost. Mustaine re-recorded the vocals for "Prisoners" and "Rust" and used B-take vocal tracks for the other two.
Mustaine made numerous changes to Cryptic Writings as well - the most commonly cited ones are the removal of the "Needles And Pins" sample from the intro to "Use The Man", the addition of heavier guitars to "A Secret Place" (and pushing the sitar way back in the mix), new intros to "The Disintegrators" and "Have Cool Will Travel", and an additional guitar and no echo on the vocals on the chorus of "Almost Honest",. There are subtle other mixing differences like Vortex's intro no longer fades in but starts cold, and Almost Honest has much better separation in the mix. It is said these were Mustaine did this to remove the pop elements and turn it into more of a metal album. Generally, fans like some of the changes and dislike some others. "Cryptic Writings" is not as popular as the band's other albums nor is it as notorious as "Risk", so it enjoys a cult fandom.
Dave himself wanted to do further work on the really poorly-produced So Far, So Good...So What!, but invoked this trope as a justification: he had been pissed off by Jimmy Page's remastering of Led Zeppelin albums that took out all the superfluous squeaks and details. Ironic, since later remasters removed several of those.
Countdown To Extinction and Youthanasia have the drums sounding considerably muted, as if the high frequencies have been filtered out. This is especially apparent by comparing the intro to Skin O My Teeth on both versions of "Countdown".
The band's new album, Super Collider, seems to be getting this reaction so far due to its more rock-oriented sound.
Tough Act to Follow: Endgame is sometimes considered by fans to be one of Megadeth's best albums, while TH1RT3EN is heavily YMMV in comparison to it.
A much earlier example is "Peace Sells...But Who's Buying?", which was followed by the rushed "So Far So Good So What".