If you're all alone when the pretty birds have flown,

Honey I'm still free - take a chance on me...
'Take A Chance on Me', Abba (Ulvaeus/Andersson/Anderson)

Every spring, titans of European popular music assemble for the annual Eurovision Song Contest. Starting way back in the heady mists of time (well, 1956 actually), there's little that excites a country's national fervour more than Eurovision. Well, except perhaps sport and politics and other stuff like that. Despite all of the bickering (and suspiciously partisan voting... Greece and Cyprus apparently always giving each other douze points for instance), there's one thing that every European country still agrees on - that ABBA were the greatest, most influential and most successful winners of the contest ever.

It was in 1974 that the Fantastic Four beat off Olivia Newton-John to claim the coveted crown in Brighton. But what exactly do we know about the Super-Swedes?

• What did Agnetha, Frida, Benny and Bjorn do before joining ABBA?

• What's their most successful single release around the world, both in terms of chart position and record sales?

• Are there any 'lost' songs or album tracks that you wish more people knew about? Share your favourite!

• What's the greatest video ABBA ever made? And why did they keep doing those soft-focus profile shots in the snow?

• Do you have an particular ABBA outfit that makes you lunge for your blue eyeshadow and blonde wig?

• How do you rate the bandmembers' post-ABBA work? Solo songs, stage musicals... and maybe a reunion?

• What truly is the legacy of ABBA - pioneers of '70s kitsch or a truly innovative musical act?

The best contributions to this topic may be used for a future Edited Entry.