Let me preface by saying that in no way, shape, or form is there anything about this list that is attempting to be definitive. There are tons and tons of excellent tunes that would fit the bill here, so I'm just cherry-picking a few immediate favorites!
Manowar, "Metal Warriors," from The Triumph of Steel (Atlantic, 1992)
Shit, this list could've consisted of Manowar songs alone: "Metal Daze," "Gloves of Metal," "Kings of Metal," and so on. But "Metal Warriors" has got to be one of the most epic and borderline hilariously badass metal anthems ever written. Period! Hearing for the first time, "If you're not into metal, you are not my friend!" was just staggeringly awesome. And that chorus?
Heavy metal or no metal at all! Wimps and posers leave the hall!
Priceless. It's hard to believe this song is from the '90s!?
Hittman, "Metal Sport," from Hittman (Steamhammer, 1988)
Rather than being about heavy metal, this 1988 ripper is—I'm guessing—likely inspired by the 1975 dystopian sci-fi "classic" Rollerball. You can tell from the ominous, droning synths and feedback during the intro that the tune'll be a keeper; and sure enough its crunchy, textbook metal rhythms and catchy, pumping chorus totally hit the spot. I didn't get into Hittman until a year or so ago, which is a damn shame, 'cause I would've been all over this jam back in the day, too.
Lizzy Borden, "American Metal," from Love You to Pieces (Metal Blade, 1985)
I'm not a patriotic guy or anything, so I admit that thematically this one's a little goofy, but the songwriting itself is practically flawless. Yeah, at about six minutes they probably should've trimmed the fat—I'd definitely drop the slightly out of tune harmonies at 3:08, and I've never been a fan of the whole drums 'n' vocals sing-along stuff (such as the break at 4:18)—but centering the song around that huge, anthemic chorus holds a lot of weight. Not to mention the sheer excellence of the lightly chugging riffs and ringing melodies during the intro.
Piledriver, "Metal Inquisition," from Metal Inquisition (Cobra, 1984)
What's not to love about the excessively over the top cheese of Piledriver? I can't take it seriously, but that doesn't mean it's not fucking awesome. Another straightforward, pounding call to arms, "Metal Inquisition" is like the dirty, violent older brother of Manowar's "Metal Warriors":
And if you're not a metal head you might as well be dead!
We're the metal inquisition... we sentence you to death... by guillotine!
Anthrax, "Metal Thrashing Mad," from Fistful of Metal (Megaforce, 1984)
Neil Turbin-era Anthrax doesn't get enough love. "Howling Furies" remains one of the band's finest moments, and "Metal Thrashing Mad" has been another longtime favorite of mine. Just one of many metal tracks about the reckless driving of mean machines, its archetypal riffing perfectly exemplifies what constitutes a straight-up, no bullshit, damn fine heavy metal song. Classic.