I saw Billy Dee Williams and a host of other random background actors in person at the RI Comic Con a couple years back. Never met anyone.
I actually had the chance to meet Oscar Isaac at an advanced screening of Inside Llewyn Davis but it was first come first serve and I didn’t show up early enough to get in (long story). One of the saddest days of my life.
Had a dream last night that I met Mark Hamill and he was awesome.