Allow me to start the ball rolling with, "Save all your Kisses for me" recorded by Brotherhood of Man. AAAAAAAAAAAAAAAAAAAAAARRRRRRRRRGGGGGGGGGGGHHHHHhhh!!!!!
P.S. "The Birdie Song" is excluded for any consideration whatsoever!

I always hated "Seasons Of The Sun" and "San Francisco"
as in "If you're going to San Francisco, be sure to wear a flower in your hair."
On the other side of it, some of the most annoying songs ever were the ones you couldn't get out of your head...

anything by U2

Just thought I'd get it in before anyone else does!

...is this a cunning plot to get an internet number one?
Definetly not the most irritating song of all time though.
This award surely goes to "Gang Bang", by Black Lace.
Absolutely horrific, as was the performance that went with it.
Interesting topic though, when you start to list these sort of songs in your head, you realise that you kind of like them really.
I hate "I Will Survive", but the world would be duller without it.
Re-"Paloma Blanca", does anyone know if this was the "guilty pleasure" song that Terry Halll played?

... but I hated Agadoo by Black Lace, and that horrible thing we threw at the Eurovision this year.

Des'ree, I think it was called "Life". Had that terrible lyric:

I don't wanna see a ghost
It's the sight that I fear most
I'd rather have a piece of toast

Arrrgghhh!

Speaking of lyrics, I heard Tavares "Heaven Must be Missing an Angel" recently. Never noticed the lyric, "Showers, your love comes in showers". It appealed to my warped sense of humour.

All the modern crap that is around know really but Crazy Frog has to be top

and Come On Eileen by Dexys. It always signified the start of "crap hour for the pissed up lads" in your local cheesey club.

Informer by Snow is pure crap

also

Mambo Number 5, Blue (Eiffel65), Islands in the stream is bloody awful too, though the Bess Gees are allowed one bad song.

Fairground Attraction yes. I will survive; listen to john otway's version. yellow submarine - too many to list.

John Otways version of "House of the Rising Sun", is one of the funniest things I have ever witnessed.
Mr Otways following are very aware that he treats the song , very much like a political debate.
For example...
J.O "There is a house in new orleans"
Audience "Whats it called??"
J.O."Its called the rising sun!"
Now, when I first saw him do this, a member of the audience, shouted out the wrong response to one of the lines, I think it was "whats it been?", referring to "The ruin of many a poor man", or whatever it is..
And John perfectly retorted..."now back to your question...!" after answering with the correct line first.
Pure brilliance.
And whilst we are on the subject of annoying songs, much as I love Pink Floyd,... "Dogs of War", yuk.