ABBA was one of the groups that shaped my youth in the 70s. I bought this CD a few years ago, and it's one of my favorites. I don't think ABBA gets enough credit for the influence they've had on pop music -- we would never have seen groups like Ace of Base or Roxette do well in North America had ABBA not been a precursor to them -- the group was actually quite groundbreaking in many ways.
The music is deceptively simple. Alot of it is great dance music, but there are also some terrific ballads on the album, from Fernando, to Knowing Me, Knowing You, to Chiquitita. Some of the lyrics are actually quite good and catchy, and the tunes themselves are totally hummable and fun to sing along with.
There are a few minor flaws with the disc -- there's no lyrics included, which I found really frustrating because there are a couple songs I couldn't quite figure out all the words to. Not sure if that's because ABBA tended to overproduce there songs, or if it's the quality of the remastering of the tape into CD form, or a combination of both. Regardless, the overall quality of the songs is so high, and the lyrics are so readily available on various internet sites (just do a search, they're easy to find) that this one small detail isn't important enough to take off a star.
In short, ABBA is the best -- skip all the ABBA wannabe groups and go for the original.