Sound of the underground - Girls Aloud.
Actually it isn't crappy, it's frigging boss - but they were crappy.
Maybe it belongs in ! great songs by crappy artists thread! 
https://www.youtube.com/watch?v=V9Wv4SCBiTE
Blasphemy, an tha! I love Girls Aloud, my favourite girl group ever! I don't think they were a crappy group at all. Okay, they're not the greatest singers alive but for a girl group they were perfectly suited and Nadine and Nicola are actually decent singers. They had the right image and put on great live shows. For me though, what set them apart from just about any other pop group before or since them was, quite simply BRILLIANT SONGS! I think the songs that the Xenomania team wrote and produced for them were fantastic - perfectly crafted, classic pop songs. Really strong melodies, fun, catchy, punchy, offbeat and DIFFERENT! Different with regards to the structure of their songs, I mean. Their songs (Sound Of The Underground and a few others aside) were rarely traditional "verse, chorus, verse, chorus, bridge, chorus to fade" affairs. They had unusual song structures, often sounding like several songs rolled into one and I loved that about them. Forget the cheesy videos, just listen to a track like Biology:
https://www.youtube.com/watch?v=bBPtP4t2J1kand tell me that's not a perfect pop song! Lol. It has many different parts to it and it's so damn catchy and they sing it well.
Another brilliant song, so different to anything else around at the time, or since:
https://www.youtube.com/watch?v=owJHNSF9bm0and this:
https://www.youtube.com/watch?v=Wy3SV2fvoG8They didn't follow any trends, they carved their own path. I really miss Girls Aloud. Other girl groups' and pop stars' songs I generally find so bland and generic (The Saturdays, Little Mix, Fifth Harmony, etc) with all the usual guest rappers and the same old club dance beats by the likes of Calvin Harris and David Guetta that all sound exactly the same to me! Apart from a handful of lousy cover versions they recorded there are very few Girls Aloud songs (their b-sides were usually as good as their a-sides and many great album tracks) that I don't like!
One more:
https://www.youtube.com/watch?v=lK7oOVp7BJE