Your plagiarism suspects

[the hum]

That is, not the well documented examples or the ones that have actually ended up as court cases, but stuff you've heard that makes you sit up and go "hang on, that sounds awfully like..." Perhaps they're conscious rip-offs, perhaps they're not. But to you they should definitely be filed under suspicious. Anyway, Exhibit A:

Fleetwood Mac - Everywhere https://www.youtube.com/watch?v=YmLW12Vkm6w

vs

'til Tuesday - Love in a Vacuum https://www.youtube.com/watch?v=c0p6-l0Cl-0

The latter predates the former by about two years. Listen to the choruses back to back.

[Sydward Lartle]

Listen to Sara by Fleetwood Mac, then listen to Here Comes My Girl by Tom Petty and the Heartbreakers. Or if that doesn't grab you, the Changingman by Paul Weller followed by ELO's 10538 Overture.

Then there's Watch Your Step by Bobby Parker vs I Feel Fine and Day Tripper by the Beatles, or Where is My Girl by Robb Storme and the Whispers vs Substitute by the Who.

[DrGreggles]

https://www.youtube.com/watch?v=yieWHbsvu98

[chippedandbattered]

Listen to Sara by Fleetwood Mac, then listen to Here Comes My Girl by Tom Petty and the Heartbreakers. Or if that doesn't grab you, the Changingman by Paul Weller followed by ELO's 10538 Overture.

Then there's Watch Your Step by Bobby Parker vs I Feel Fine and Day Tripper by the Beatles, or Where is My Girl by Robb Storme and the Whispers vs Substitute by the Who.

I think Watch Your Step lends more of a "feel" to I Feel Fine than straight ripping off of licks or chord progressions. I Feel Fine is better too :D

[Dead Soon]

They both came out very soon apart, so maybe it's just a coincidence, but the main riff in the Sex Pistol's Holidays in the Sun and The Jam's In The City sound noticeably alike - perhaps the Burton Suits attended an early Pistols gig and the riff stood out to them.

[Rocket Surgery]

Probably complete coincidence, this one, but always catches my ear when I hear either song:

https://www.youtube.com/watch?v=P4sANPkk3ys&t=50s

https://www.youtube.com/watch?v=xnKhsTXoKCI&t=6m18s

[Maurice Yeatman]

One for the Death Metal fans:

https://youtu.be/sQVLsvZcr34?t=14s

https://youtu.be/2-tnnbwIYys?t=5m31s

[Jockice]

And in the gravelly-voiced (sort of) Scots corner.

https://www.youtube.com/watch?v=FOt3oQ_k008

https://www.youtube.com/watch?v=tJUeHsHA-4I

[wosl]

Listen to Sara by Fleetwood Mac, then listen to Here Comes My Girl by Tom Petty and the Heartbreakers.

I don't think these are especially similar (I'd say the same about the two cited in the OP).  In any case, the respective albums that these two tracks came out on were apparently released only a week apart - Tusk came out seven days before Damn The Torpedoes, according to Wiki - so such similarities as there arguably are would be coincidental (unless we're suggesting that Stevie and Tom, who are/were acquaintances, had played demos to each other in the weeks and months leading up to recording, and had fallen prey to a bit of subconscious absorption).

[Steven]

I've got a Fleetwood Mac one, the riff from Rhiannon sounds to me to have been inspired by Doc Watson's cover of Windy & Warm and they're both in the key of Am.

The opening melody/feel of Lemar's If There's Any Justice is taking from Dionne Warwick's Walk On By.

All of the melody of Deep Purple's Child In Time is nicked off It's A Beautiful Day's Bombay Calling.

[wosl]

I've got a non-Fleetwood Mac one: just a detail, but the small repeating guitar figure that features in One Step Nearer The Edge by The Tourists is surely lifted from Pink Floyd's Fearless.[nb]Someone'll probably arrive in a minute to point out that they both half-inched it from something by Bach[/nb]  Really good and under-appreciated band the Tourists, nevertheless; best thing Stewart and Lennox were involved in by the length of several straggly semi-permed ginger mullets laid end-to-end.

[Custard]

Charlotte Gainsbourg's Got To Let Go sounds an awful lot like MIA's Paper Planes

https://youtu.be/_TIR6mkyn1Y

Coincidence, I'm sure!

[Brundle-Fly]

I think this is the most flagrant rip off of recent years. On hearing it for the first time, Jarvis Cocker must've performed more double takes than that Venetian pigeon from Moonraker (1979)

https://www.youtube.com/watch?v=XOQD-h_dRbg

Paul Weller similarly
https://www.youtube.com/watch?v=7miErQzz4Y8

How did this band look at themselves when racking them out?

[Avril Lavigne]

Santigold's 'Disparate Youth'
https://www.youtube.com/watch?v=mIMMZQJ1H6E

is a really blatant ripoff of XTC's Making Plans For Nigel, even down to the wordless backing vocals in the verses which have just been changed from 'oo-ooh' to 'aa-aah'.
https://www.youtube.com/watch?v=s29RKnB7l7o

[Brundle-Fly]

Santigold's 'Disparate Youth'
https://www.youtube.com/watch?v=mIMMZQJ1H6E

is a really blatant ripoff of XTC's Making Plans For Nigel, even down to the wordless backing vocals in the verses which have just been changed from 'oo-ooh' to 'aa-aah'.
https://www.youtube.com/watch?v=s29RKnB7l7o

Never made that connection but yes. I think Disparate Youth is very original in its own way though

[thecuriousorange]

The verse of Let Me Entertain You is the verse of Jesus Christ Superstar.

[Steven]

The verse of Let Me Entertain You is the verse of Jesus Christ Superstar.

I've always thought it was more a ripoff of Sympathy For The Devil.

[machotrouts]

Comedy Icelandic Eurovision flop Silvia Night's 2007 single 'Thank You Baby'.

Britney Spears' 2011 Femme Fatale bonus track 'Don't Keep Me Waiting'.

Is that not more or less the same song sped up a bit?

Strange to hear that a comic character masquerading as a popstar might have plagiarised Silvia Night hahaha good one machotrouts.

[the hum]

Muse - MK Ultra https://www.youtube.com/watch?v=27ixLv3Lw1M

I actually find it quite endearing that they seemed to borrow heavily from the Treasure Hunt theme in writing the above: https://www.youtube.com/watch?v=xEV5bVDb9m8

[The Masked Unit]

There was an interesting article in the guardian yesterday about Ed Sheeran's recent infringement.  It quoted a forensic musicologist who said that coming up with the same structure/melody as another song accidentally is a mathematical near impossibility.

[armful]

This Pixies songs

https://www.youtube.com/watch?v=zvnT_xLCGvQ

This Weezer  Song

https://www.youtube.com/watch?v=JaqdUccgdoE 



To my ears  similar beasts 

[Steven]

^^ Weezer actually admitted they accidentally/subconsciously plagiarised the riff for Undone (The Sweater Song) from Metallica's Welcome Home (Sanitarium) and note they both also have bracketed subtitles.

[Twed]

Has somebody recreated the cover of Doolittle using a paint package's airbrush tool there?

[Depressed Beyond Tables]

A trio:

Take Me I'm Yours - Squeeze

https://youtu.be/ERQgvSZFLPE?t=35

This is not a Love Song - PIL

https://www.youtube.com/watch?v=Az_GCJnXAI0

Jizz In My Pants -  The Lonely Island

https://www.youtube.com/watch?v=4pXfHLUlZf4

[greenman]

I've got a non-Fleetwood Mac one: just a detail, but the small repeating guitar figure that features in One Step Nearer The Edge by The Tourists is surely lifted from Pink Floyd's Fearless.[nb]Someone'll probably arrive in a minute to point out that they both half-inched it from something by Bach[/nb]  Really good and under-appreciated band the Tourists, nevertheless; best thing Stewart and Lennox were involved in by the length of several straggly semi-permed ginger mullets laid end-to-end.

The Charlatans Here Comes a Soul Saver does it even more obviously...

https://www.youtube.com/watch?v=ivMIg8X5-eI

[wosl]

Haven't heard that before, but yeah, that one's so obvious you'd have to say that it's hands-up, open mimicry.

[Serge]

Charlotte Gainsbourg's Got To Let Go sounds an awful lot like MIA's Paper Planes

https://youtu.be/_TIR6mkyn1Y

Coincidence, I'm sure!

To be fair, 'Paper Planes' is based heavily on a sample of 'Straight To Hell' by The Clash, so Gainsbourg is ripping them off rather than M.I.A. I suspected that Beck might be behind it, having produced one of her earlier albums and having never had an original idea in his life, but it turns out that it was written by some git from Noah And The Whale.

Paul Weller can't help himself - The Jam's 'Trans-Global Express' is a complete rip-off of 'So Is The Sun' by World Column. Weller fans may also recognise the beginning of Hot Rod Poppa by Marsha Hunt, though I suppose that's more of a sample than a nick.

[Mr Banlon]

Cherry Cherry, Neil Diamond https://www.youtube.com/watch?v=hlcuAsgc5-c
The Romantics, What I Like About You  https://www.youtube.com/watch?v=Rqnw5IfbZOU

Stones, Torn and Frayed : https://www.youtube.com/watch?v=hJtfANIjmQM
Charlatans : https://www.youtube.com/watch?v=blqPQP7RPXw

Australian Crawl : https://www.youtube.com/watch?v=oxqreCG0htQ
Guns n Roses : https://www.youtube.com/watch?v=1w7OgIMMRc4

[Mr Banlon]

Tamba Trio :  https://www.youtube.com/watch?v=RMOKkSxWdKA
Signor Rossi :  https://www.youtube.com/watch?v=RMOKkSxWdKA

[thecuriousorange]

The opening bears more than a passing resemblance to Champagne Supernova.

http://www.dailymotion.com/video/x6tvj_red-hot-chili-peppers-soul-to-squee_music