Some strange selections there, folks!
I'd rate the following, in no particular order:
Tar & Cement, Joe Dolan
Walking The Streets In The Rain, Butch Moore
Papa ooh Mow Mow, Freshmen
Love Is A Symphony, Roly Daniels

A tremenduous song from the 60s was "Never An Everyday Thing" by Grannys Intentions, although as they were more a beat group than showband,  maybe they should not be included here.

There's a long list of showband (and other) hits listed here:
http://www.munster-express.ie/050513/opinion1.htm