What are your top 5 Billboard top 10 songs of the 1970"s?

These don't meet the OP's criteria; but, they probably should have:

You Got Me Anyway - Sutherland Brothers
I'll Be The One - Badfinger
Dirty Work - Steely Dan
Planet Queen - T Rex
I'm On Fire - Dwight Twilley Band
Pretty Lady - Lighthouse
Until You Come Back To Me - Aretha Franklin
Woman To Woman - Joe Cocker
Thunder and Lightning - Chi Coltrane
Ooh La La - The Faces
Hold On - Ian Gomm
No Time To Lose - Tarney - Spencer Band
Can't Live My Life - Crabby Appleton
Star - Stealers Wheel
Born To Wander - Rare Earth
Schoolboy Crush - Average White Band
Running back To Saskatoon - Guess Who 

I don’t think the OP was suggesting that defined "good music". He was simply teeing up some input and reflection - of that category what did you like best?
It didn’t define good music, but it certainly contained A lot of it.
The second half of the 70’s was the beginning of corny.

I guess I don’t understand why someone wants to talk just for the sake of talking. Not the best. Not the worst. OK, just memories. But I never paid any attention to top 40. it was filler IMO. But thats me.
I will agree that a lot of good music was top 40. A blind squirrel findas a nut sometimes. One example I remember was a song by

Diesel - Sausolito Summer Nights. Give it a listen
(1) Diesel - Sausalito Summer Nights - Bing video

as to corny Music in the last half, let me remind you that The Wall and Breakfast in America both came out in 1979. There are plenty others but 'Disco" overshadowed the good music being put out

100 Greatest Albums of 1979 (digitaldreamdoor.com)

Making a list soon.

Mitchagain Tarney-Spencer Band is definitely a favorite of mine too!

Atlanta Rhythm Section Eileen
Pure Prairie League Aimee
Rod Stewart Maggie May
Foghat It Hurts Me Too
Michael Stanley Band Lets Get the Show on the Road

Ask me again tomorrow and I will recall 5 others that were impact ful and meaning full to me. Great thread!