Yeah, you can listened to a track here.
http://gbv.com/sounds/deathoftheparty.mp3

I would have to go with Running on the Spot by the Jam.

Gosh, there are so many.
Here's three that rush to mind:

"Teenaged Kicks," The Undertones
"Someday, Someway," Marshall Crenshaw
and, a sentimentall favorite, The Other Ones' "Another Girl, Another Planet."
Can't go wrong there.

john

ps: honorable mention to Tom Robinson Band's "2,4,6,8, Motorway."

You know, the Only Ones occupy a very important spot in my musical world, and I just don't think of them as power pop, exactly, but I can see how one could. We used to do "Lovers of Today" for a while in the latter day dB's.

oh my gosh, I think I've released a fire hose worth of good music picks ...thanks so much for everyone's suggestions. Pete

I find it a bit difficult to define exactly what "power pop" is. I know it when I hear it--and I agree with most all of what has been listed here, especially Big Star. Per my vague definition, I have to add early Cheap Trick, in particular "Takin' Me Back" from the "Heaven Tonight" album.

Best? That's tough. There are quite a few jems.

the Records - Teenarama
the Beat (Paul Collins') - Rock and Roll Girl
Bram Tchaikovsky - Girl of My Dreams
the Plimsouls - Everywhere at Once
Rockpile - Play the Fast Thing (One More Time)
the Speedies - Something on My Mind/Time
Let's Active - Every Word means No
Feelies - Fa Ce la

Those get regular spins on my digital jukebox.

1.Black And White(dB'S)
2.That's What the Little Girls Do(The Knack)
3.Yellow Pills(20/20)
4.On And On(Pezband)
5.Pretty Baby(Blondie)
6.Too Late(Shoes)
7.Lies(Knickerbockers)
8.September Gurls(Big Star)
9.Abracadabra(Have You Seen Her)(Blue Ash)
10.American Squirm(Nick Lowe)
11.No Matter What(Badfinger)
12.any original off Beatles VI
13.Everything Works If You Let It(Cheap Trick)
14.Couldn't We Talk About it(Todd Rundgren)
15.Why Are You Walking Out On Love?(Paul Collin's Beat)
16.Houdini Love(Fingerprintz)
17.Hearts Will Be Broken(The Records)
18.My Girl MaryAnne(Spongetones)
19.I'm The One That's Leaving(Bram Tchaikovsky)
20.Duchess(The Stranglers)

I know some of these were released before '78,but power-pop just the same.Boy,that was fun!!
Thanks,
Adrian
p.s. If any one could assist me in a copy of that 1st lp by Nervus Rex and also the one by Buddy Love I'd be gratefully indebted to you!R'n'R thanks!!

Icicle Works - Birds Fly
Bangles - Hero Takes A Fall
Marshall Crenshaw - Hold It
Undertones - It's Going To Happen!
The Church - Unguarded Moment.
I hope someday this music will get the re-issue attention it deserves. We're out there.

Quite possibly my favorite power pop song of all time is "You Got It (Release It)" by Pearl Harbor and the Explosions.