“Let’s Go All the Way” sounds like a Prince song to me. I’m not catching any resemblance to the Beatles.
I can sorta see a “I Am the Walrus” tangentially in there. Each verse line kinda starts of like the pattering verses of “I Am the Walrus,” but severely truncated. Some of the string melodies and psychedelic keyboards in the background also evoke that era of Beatles. The chorus, I don’t really hear Beatles in, but I can see how this can evoke Beatles.
Ditto. It doesn’t even really sound like Green Day to me, but I suppose I follow music a little more closely than the average bear. (Like the singer doesn’t sound like Billy Jo, the drums don’t sound like Tre Cool, and the general vibe and production of the song isn’t quite Green Day to me.) That said, most people can’t pull the name Harvey Danger out of their ass, so you’d win the bet. Harvey Danger only had this hit song, and – honestly – the only reason I know it is not because I heard it on the radio, but because it became the theme song to “Peep Show” from the second season (I think) onward, and I looked it up, wondering what the title of the song was and who performed it.
There’s a cool story about the song and the band here, if you’re interested in that sort of thing:
This is the winner of the thread for me. But, 74westy beat you to it a few posts up. 
That’s what I get for not double checking the whole thread.
I think it resembles “Why Don’t We do it in the Road”, at least lyrically.
To be fair, I remarked it sounded like what the Beatles might have sounded like, if they were still around in 1986. Maybe Paul borrowed from Prince. 
If I had put the name of the song in the text of the post it would have been easier to find but I was trying to be cool.
Since this thread has morphed from songs that sound like covers to bands that sound like other bands, for me the big one was discovering “Cruel to Be Kind” was not an Elvis Costello recording, but a Nick Lowe song. Granted, the two were intertwined, so I suppose the mistake is understandable, but I was gobsmacked (before I knew more about Nick Lowe) that it wasn’t Elvis’s track.
Oh, I got one in terms of the original thread. When I first heard Matthew Sweet’s “Girlfriend,” I was convinced it was a cover of some 60s song. I was probably reminded of Jefferson Airplane and “Want Somebody To Love” because of the lyrics, but it wasn’t until at least several weeks later I figured out (or someone told me) that it was an original.
The DeFranco Family sounded remarkably like The Jacksons.
ETA: that opinion is from a classic rock DJ, not just me.
Anything by Greta Van Fleet has me do a double-take, until I realize they’re not Led Zeppelin.
Tripler
They sure as hell rock close-to, but not as good as Zeppelin. 
This puzzles me a bit. The production of “Girlfriend” (the song and the whole album) gives it away as a early 90s production. As bone dry and direct as it is produced (and that was deliberate, Matthew Sweet wanted it to sound exactly like this), it sounds a lot different than 1967 Jefferson Airplane at the height of psychedelia.
The original thread was about songs you thought were covers. I knew “Girlfriend” was a current song, of course. But it sounded like a song I had thought I’d heard before and it was a current take on it, ie a cover.
Ok, understood, I can see that the song itself could have been from the 60s. Though I’d rather thought of the Beatles than Jefferson Airplane.
Yeah, it’s not specifically Jefferson Airplane, but it’s clear that’s probably where the thought came from, due to the lyrics.
I know I have a bunch of these, where I know the performing artist but I could swear it’s a cover of an older song. The production is irrelevant; the recording doesn’t have to sound anything like the “original”; it’s the songwriting. There’s a current one on the radio that sounds to me like it’s a cover of a John Prine song, but I suspect is an original. For the life of me, I can’t conjure up its name or the performer. That one sounds a bit more like the “source” material, though.
Yeah, the cadence of the verses of “Let’s Go All the Way” does bear some resemblance to “I Am the Walrus”, once you point it out.
Speaking of Zep sound-alikes: who could forget Kingdom Come.
It’s a LZ pastiche. I don’t think the band tried very hard to deny that’s what they were going for - for commercial purposes. I remember a quote from their manager: “I’m not gonna lie - I’m in this for the money.”
Has there ever been a rock manager who wasn’t? 
When I first heard this song, I thought it had to be a deep cut from one of John Lennon’s early-'70s solo albums.
Tame Impala – “Feels Like We Only Go Backwards” (2012)
Cover? Some say yes, some say no (after all the Zep rip offs of classic blues, it’s fitting).
