I am a big fan of the original Founders at Work book (I reviewed it here previously), and now it seems that a European variant has been published:
I am really looking forward to reading this one, as there are some interesting companies listing in the table of contents from the Amazon page:
1. MessageLabs 2. Shazam 3. XING 4. Business Objects 5. TweetDeck 6. Balsamiq 7. Dailymotion 8. Moo.com 9. amiando 10. Prezi 11. Video Island (LOVEFiLM) 12. The Next Web 13. Seedcamp 14. Yandex 15. Last.fm 16. Startupbootcamp 17. Fon 18. lastminute.com 19. Seesmic and LeWeb 20. SoundCloud
Updated 2022 : note that the above post was originally published in 2012, but is left here for archival purposes. I have fixed some broken links above.