Danish

All 7 in 1st and book club 1st editions. 1 and 2 I have so far only found in 1st book club edition. The difference between those and normal 1st edition is the "Gyldendals bogklubber" text and numbers on the spine. Except for the 5th book, which was released in an alternate cover for the book club version.
Cover illustrations by Per Jørgensen
ISBN:
87-00-63162-0
87-00-63796-3
87-00-39628-1
87-02-00127-6
87-02-02222-2
87-03-00004-4 (book club HP5, alternate cover)
87-02-04122-7
978-87-02-06228-1

1st edition book club editions. Book 2 and 3 - 3 with pre-movie font
Cover illustrations by Per Jørgensen
ISBN:
87-00-63796-3
87-00-65233-4

5th edition softback. The page edges are black.
ISBN:
9788702113990
9788702114331
9788702114348
9788702114362
9788702114393
9788702114423
9788702114430

Danish 1, 2 and 4 hardback 6th edition. Cover illustration: Jonny Duddle.
ISBN:
9788702173222
9788702173239
9788702173253

1, 3, 4, 6 and 7 in 8th edition softcover. Cover illustration: Brian Selznick
ISBN:
9788702272451
9788702272468
9788702272475
9788702272499
9788702272420

1 and 6 CD audiobooks.
7 MP3 audiobook.
Read by Jesper Christensen (who pronounces all names really bad)
ISBN:
?
87-02-04498-6
9788702075441

2nd edition (Hardback). Cover illustrations by Per Jørgensen
ISBN numbers:
87-00-39836-5
87-00-45994-1
87-00-47046-5
87-02-00280-9
87-02-02944-8
978-87-02-04851-3
978-87-02-06999-0

2nd edition (Hardback). Cover illustrations by Per Jørgensen.  Older print runs with pre-movie font.
ISBN numbers:
87-00-39836-5
87-00-45994-1

 3rd ed. Only the first 4 books were ever released in this edition.
ISBN:
87-02-02769-0
87-02-02770-4
87-02-02771-2
87-02-02772-0

Special edition "The Collection" from 2008. Limited run with certificate with serial number in the box. The box is black painted wood with embossed logos. The inside is lined with velvet. I have one set with the box and one set without.
ISBN:
978-87-00-77463-6
978-87-00-77465-0
978-87-00-77467-4
978-87-00-77469-8
978-87-00-77473-5
978-87-00-77475-9
978-87-00-77477-3