The Final Countdown is an overrated album (I think Prisoners In Paradise is Europe's best by far), but I think mainly its the title track that is overrated. The best songs on the album are Heart Of Stone, Rock The Night, Carrie, and Danger On The Track. And I agree with Blitz about Appetite. I think it is a fantastic album but certainly not in the top 5 of the '80s like most people seem to think. I mean there are better albums just from 1987 let alone from the whole decade.
By the way, The Final Countdown wasn't a 1987 release anyway, it was 1986.
Hysteria though, in my opinion, is simply one of the greatest achievements ever in rock music. There are 2 songs though that I skip (Excitable & Rocket, don't like those 2), but apart from that its perfect melodic rock. Nobody has ever achieved such unique & melodic sounding twin guitar textures as Steve & Phil do on that album, the backing vocals are the best ever recorded and just massive, the production is absolute perfection, and every song is memorable and ultra-catchy and stands out, no two songs sound the same and none come across as filler (even the 2 I don't like, I just don't like the feel & melodies in those 2 songs).
And then when you also take into account all the trouble Def Leppard had recording that album, makes it an even greater achievement. They were literally on the brink of band not even existing anymore and had to record the album over a long period of time in spurts because the whole band was pretty much never together at the same time to do it, and it had to come together with lots of mess & complications (Steve in rehab, Rick in hopsital then still learning how to play his customized kit with one arm while he was recording, etc)... and somehow they came out with one of the biggest selling rock albums of all time that not only matched Pyromania's success but way outdid it had seven hit singles spawn from it. Amazing!