It's late, I can't see well and I'm...OK, I'm too lazy to check back 20 years to see if this has been addressed. Besides, lots of good cover tunes out in recent years (Disturbed on "The Sound of Silence", e.g.).
So...has to either be a rock tune originally or on the re-make. Other than that, no rules. I'm not looking to rank these. Just too many and I don't need that headache. Just some good ones. Well, no Knocking on Heaven's Door, as a full 1 million acts have covered that. Also, no Weird Al type parody songs (props, however, for his appearance in Weezer's cover of Toto's Africa).
I'll start with one of the more obscure, as I love that especially, and it's so unexpected. Iron Maiden covering Jethro Tull's Cross-Eyed Mary, complete with Harris's galloping bass. (I'm also not going to use quote marks...this isn't an appellate brief).
The Wilson sisters and Jason Bonham joined up with a good backing band and singers to do a KILLER Stairway to Heaven at the Kennedy Center, where the surviving members of LZ were being honored (YouTube that).
Jimi Hendrix covering Dylan All Along the Watchtower is a classic.
Johnny Cash cover of NIN's Hurt is simply amazing.
Korn covering Cameo's Word Up is pretty damned fun.
Judas Priest covering Fleetwood Mac's Green Manalishi (live version only, please)
In This Moment does a good cover of Phil Collins's In the Air Tonight (yes, it's been covered a bunch, but this is probably my favorite version). They did an even better version of Blondie's Call Me
Alien Ant Farm's cover of Michael Jackson's Smooth Criminal is quite good, and the video is hilarious.
Bad Wolves did a good cover of The Cranberries' Zombie, but sad back story to that one. Dolores O'Riordan was supposed to sing on the album, but drowned in her London hotel room bathtub after a few drinks before she could complete the task.
Most anything the original Blues Brothers did. Also, pretty much the entire cover EP Rush did (Feedback).
Of course, Clapton did a couple such as Crossroads and something about booger sugar.
Saw Blues Traveler in New Orleans earlier this year cover Charlie Daniels' The Devil Went Down to Georgia, and John Popper played the fiddle solo on a harmonica, note perfect. That was simply astonishing, just not sure if there is a video of it anywhere. Primus did a cover, but I'm not sure either end of that could really be considered rock...it sure was when Blues Traveler played it. B T also did a great cover of Tom Petty's Last Dance With Mary Jane, and the House of Blues had all green lights going in the venue. Very cool.
Two nights later, saw Pink cover Nirvana's Smells Like Teen Spirit, which was great. Also did one other really good cover (cannot recall what one now).
Wait a minute. Wasn't at this particular show, but here's Blues Traveler's take:
Others? I'll likely add to this OP as more come to mind.