I've seen loads of designers during the shows/showrooms/parties, but here are the ones I've actually chatted with:
Peter Jensen, Sophia Kokosalaki, Mark Eley, Kim Jones, Alexander McQueen, Lutz, Katharine Hamnett, Robert Cary Williams, Marjan Pejoski, Jonathan Saunders, Richard Nicholl: all tutors or visiting lecturers at my former college, everyone was nice excluding Katharine (cuckoo) and McQueen (drugged)
Raf Simons, Veronique Branquinho, Dries van Noten, Walter van Beirendonck: All very nice (For some reason Belgians mingle well with Scandinavians)
Rei Kawakubo and Junya Watanabe at a casting (they were scary) plus Marc Jacobs at LV (boring as hell, like his work)
Tom Ford and Zac Posen at a lecture...both seemed annoying and self-centered