I have been to quite a few conventions.
Jonathan Frakes (x3)- fantastic all three times
Marina Sirtis - was great and remembered my daughter and I at the photo op
Avery Brooks - took time for everyone in line. Long line but so friendly.
Gates McFadden - filled in once when J. Frakes couldn't get there do to snow storm in Maine. She was great and very friendly.
Walter Koenig - my first con. very nice but low key.
Michael Dorn - nice but also low key.
James Doohan - great story teller. friendly but rushed.
Majel Barret - nice but quiet.