I remember back in 1997 I was always hearing Wham!'s Careless Whisper on the radio but mistakenly thought it was the Richard Marx song Should Have Known Better instead, so when I eventually got Richard Marx's debut album on cassette that Christmas I was in for the shock of my life when Should Have Known Better came on sounding nothing like Careless Whisper. I eventually found out the song I had grown to love was by the group Wham! and was really called Careless Whisper instead, but boy did I feel stupid thinking I was getting something with a particular song on it then finding out it was completely different.

Also when I first heard the N'Sync song I Want You Back way back in 1998 I thought that the Backstreet Boys were already coming out with a new album less than a year after I got their first one. 1997 and 1998 sure were confusing years for me lol.

Someone mentioned 10CC earlier. Their great song Rubber Bullets always sounded to me like the Beach Boys backed by a 70's hard rock band.

I think it sounds more like Edison Lighthouse, White Plains, and The Brotherhood Of Man.

But not so much like The Pipkins.

When I first heard "Show Me The Way" by The Storm, I thought it was Steve Perry.

I always thought that "Love My Way" by the Psychedelic Furs sounded kinda like Bowie on quaaludes, but in the liner notes for the "Forever Now" 2002 re-issue, singer Richard Butler admits "... I'd been listening to Scary Monsters - that might have informed it a bit - and I came up with this vocal melody and all the words within about an hour ..."

There are several songs on the debut record from Lilys, In The Presence of Nothing, that might as well be My Bloody valentine outtakes, they're so note-for-note perfect.

Later, Lilys would do an outstanding impression of The Kinks and early Who on Better Can't Make Your Life Better, most notably with "A Nanny in Manhattan," "Shovel Into Spade Kit" and "Who Is Moving."

Another thread just reminded me of this one: when I first heard Martin Page's "In The House Of Stone And Light," I was sure it was Sting.

When I first heard "Dream On" by Aerosmith, I thought it was Led Zeppelin.

I like their later work, but STP's "Sex Type Thing" is a bold-faced Pearl Jam ripoff.

When I first heard "Video Killed The Radio Star" by The Buggles I thought it was ABBA.

Every now and then I find a Robyn Hitchcock or Soft Boys tune that I haven't heard before and my initial instinct is, "Syd Barrett bootleg?"

When I first heard Dream On, I had no clue who it was, but I loved it. It happened to randomly play while I was taping a couple hours of a radio new release show on a reel to reel machine at the age of 16 or so, & I remember playing the song repeatedly for my friends.

Perhaps I missed the O/P's point, but I can't believe this thread got through three pages with no one mentioning:

Starcastle / Yes and

Triumvirat / Emerson, Lake and Palmer.

Minor differences, yes, but otherwise very nearly clones!

A couple more that I don't believe anyone has mentioned that always KILL me:

Los Bravos "Black Is Black" sounds exactly like Gene Pitney. To this day, I listen to it and can't believe it isn't him.

Andy Kim "Rock Me Gently" sounds a lot like Bang era Neil Diamond.

I had completely forgotten about "The Walls Came Down" by the Call. What a great tune that was!

Did Gene Pitney sing English phonetically, with a German accent?