The Top 100 Norwegian songs since 1980, according to radio listeners

3. Turbonegro: Get It On
5. a-ha: Take On Me
6. Turbonegro: The Age Of Pamparius
10. Turbonegro: I Got Erection
11. Motorpsycho: The Nerve Tattoo
12. Madrugada: Majesty
14. TNT: 10.000 Lovers
23. a-ha: The Sun Always Shines On TV
27. a-ha: Hunting High And Low
30. Motorpsycho: Nothing To Say
33. Madrugada: The Kids Are On High Street
36. a-ha: I’ve Been Losing You
41. Satyricon: Fuel For Hatred
44. Kings Of Convenience: I’d Rather Dance
45. Röyksopp: Eple
47. Ralph Myerz & The Jack Herren Band: Nikita
49. a-ha: Stay On These Roads
56. Kings Of Convenience: Toxic Girl
61. Lene Marlin: Unforgiveable Sinner
62. Motorpsycho: Slow Phase Out
63. Magnet: Where Happiness Lives
64. Morten Harket: A Kind Of Christmas Card
66. Röyksopp: Poor Leno
69. Bel Canto: Shimmering Warm And Bright
75. Röyksopp: Only This Moment
79. Annie: The Greatest Hit
81. Bertine Zetlitz: Adore Me
82. Röyksopp: So Easy
87. Sondre Lerche: You Know So Well
88. Fra Lippo Lippi: Shouldn’t Have To Be Like That
89. M2M: Don’t Say You Love Me
90. Bel Canto: Rumour
92. Biosphere: Novelty Waves
98. Erot: Song For Annie
99. Bertine Zetlitz: Girl Like You

Surprised De Lillos didn't get higher than 18, and that "Kokken Tor" of all songs would be the one to hit the highest.
Aside from that, it seems the whole "rock poet" rubbish that the media keeps piling up on Jokke's corpse is working. Three songs in the top 10!

Well, "The Greatest Hit" is in the Top 100 at least. She hasn't been making music for very long yet.

Some YSI on the four Norwegian language acts most prominently featured in the list may be in place at least:

Dum Dum Boys, Jokke & Valentinerne, DeLillos and Raga Rockers did all break through at roughly the same time during the mid to late 80s. While their music is certainly great, I think all four have gotten their position first and foremost because of their lyrics. Lyrically, they are all different, but at least apart from Jokke they do also have a lot in common.

Raga Rockers were the first of the bunch, and sort of pioneered the new way of writing lyrics. Their lyrics are kind of minimalist, with not a lot of words, but still letting the message through in a great way. "Noen å Hate" is a song about how a lot of people feel the need to have somebody to hate, covering rascism, violence, prejudice, war and "enemyship" in general. Musically, they played a rather raw rock'n'roll with punk roots. (Main songwriter Mikael Krohn also used to be a member of punk pioneers Kjøtt earlier in the decade)

Dum Dum Boys may be the band that has the most in common with Raga Rockers, musically and lyrically. Like Raga Rockers, they have a punk background (originally started out as punk band Wannskrækk) but developed their style towards a more conventional rock and changed their name into Dum Dum Boys by the mid 80s. Their lyrics are a bit like Raga Rockers' in that they, too, use few words and are kind of vague, but usually with less obvious message and more "poetry" in a way.

DeLillos are lyrically a bit like Dum Dum Boys, but mixing their lyrics with a lot of humour. They come from the West of Oslo, which is sort of the "best part of town" (like West London) and their upper middle class background became sort of an image for them.
Musically, DeLillos are more "pop" than the rest of the bunch, with less prominent rock guitars and a more melodic songwriting style.

Jokke (Joachim Nilsen) tragically died from a heroin overdose in 1999. He was always an outsider of sorts, which is heavily covered in his lyrics, which often deal with alienation, feeling useless, mental problems, but also with drinking, taking drugs and partying. Unlike the vague "poetry" of the other three, Jokke was always very direct though. He said everything he wanted to express directly without writing in "code" the way the others did to some extent.
Out of the other three, he was often compared with DeLillos' main songwriter Lars Lillo Stenberg, not at least because while Stenberg had this upper middle class background from Western Oslo, Jokke was very much a working class guy, and in some way his serious drinking and drugs problems even put him in a kind of "sub working class". Musically, Jokke was about as punk/rock'n'roll as Dum Dum Boys and Raga Rockers (frequently experimenting with genres such as ballads, ska, Phil Spector pop etc. though) but he was also more melody oriented like DeLillos. So, musically, he sits a bit in-between DeLillos and the other two, while lyrically he was in a league of his own.

Commercially, DeLillos and Dum Dum Boys were big albums sellers already in the late 80s. Jokke and particularly Raga Rockers struggled somewhat more commercially back then, but they are just as huge as the other two by now, a hit compilation by Raga Rockers having just topped the Norwegian album charts.

All four are very typically Norwegian phenomenons, which makes them hard to explain to non-Norwegians, but I have at least made at attempt. I suppose maybe Øystein could fill me in (although it seems I like those acts slightly better than he does)