I only have a few guests I'd love to see, namely musical. But here goes.
Seiyuu
Daisuke Ono
Mamoru Miyano
Romi Park
Maaya Sakamoto
Rie Kugimiya
Voice Actors
Mona Marshall (although I know she never goes to conventions ^^; )
Yuri Lowenthal
Crispin Freeman
Johnny Yong Bosch
Liam O'Brien
Musical Guests
angela
Kalafina
Yuki Kajiura
FictionJunction
Tsuneyoshi Saito
Tomohito Nishiura
Hiroyuki Sawano
Yousei Teikoku
Chikayo Fukuda
Nana Mizuki
Yuya Matsushita
Of course, anyone would be great.