These always get me.
黒百合と影’s “Benjo” is an almost direct rip of Coal Chamber’s “Loco.”
DOBE’s “性ト死” sounds…very similar to Job for a Cowboy’s “Entombment of a Machine” (at least the intro).
And perhaps my personal favorite…
Gackt’s “Another World” sounds…suspiciously similar to “3 Small Words” from the Josie and the Pussycats movie. 
The opening of “Rage” by the Gazette sounds similar to Slipknot’s “People = shit”.
Discovered this one earlier.
Gotcharocka’s ‘Shortcake’ is heavily inspired by Radwimps but what’s interesting is they actually borrowed the live rendition (the standard Radwimps single doesn’t have the drumming at the start)
I don’t usually notice these things because I have a horrible memory for remembering details of songs but these are some instances that I noticed where the songs sound pretty similar or at least have parts that sound similar:
Sounds like:
Sounds like:
Sounds like:
Sounds like:
I’ve got two more interesting ones, where the band actually copies off of themselves.
The GazettE used the same riff for THE MURDER’s TV and Maximum Impulse.
lynch. recycled the riff from NEW PSYCHO PARALYZE on the opening of EXIST. Unfortunately NPP isn’t on YouTube, but if you’ve ever heard the song you’ll spot it right away.
I struggled with whether or not I wanted to post this one, but after finding a few more similarities I’m almost certain that this is the case. I think that D.I.D.'s $howtime in the [World’s End] is based off Para:noir’s showtime in the [xxx], as much of D.I.D.'s music (but not all) is based off Para:noir anyway this isn’t that surprising. But instead of a cover this seems to be a reprise.
I was talking to someone else about this a few years ago, and I also remember the chorus on Blitz’s resembling another song. I’ve since forgotten.
I can’t pinpoint exactly to one thing, but ACME has had a string of very BMTH-like songs. It’s very much a djent thing and you hear it everywhere, but this is a bit too on-the-nose, imo.
There are so many songs that’ve I’ve done double-takes with, but it’s usually because they’re in the same key. Makes for good playlist material though.
omg if prince’s estate ever catches wind even they are in trouble. they are more open about the internet but just as serious about rights.
prince would neeeever license a part of his songs like that haha,
remember he was even angry about sugizo using a cloud guitar it seems.
hide himself recommended the SPAWN ost cd to fans so this is pretty funny haha.
pretty obvious he reworked the riff pattern from that song ^v^ but hey hide is still the best!
=
I love 去勢 but holy fuck they just combined Obscure and rotting in vain.
Omg thank you for showing this masterpiece to me. I love it. 
It’s nice to listen to a new Obscure remake in a while haha
some riffage stealage
oh also:
sounds a lot like
Some love is dead level thievery
Razors New World sounds suspiciously like Despairsray Garnet, or is it just me imagining things
My favorite trio