Avery Brooks gets the award for being the "biggest star" who is nicest. He is so deep and philosophical, yet so down to earth and friendly. He takes the time to shake your hand, ask your name. He's a man of the people, very casual. He also levels with you: he does these shows to say "hello" to the fans. He doesn't promote any projects unless you ask him directly, and even then, he tends to keep that brief! He genuinely enjoys experiencing the diversity of the fans and to see what Star Trek means. I'm left in awe whenever I meet him, because he doesn't have to do that.
100 percent agree. Avery Brooks was great when we met him at FanExpo in Toronto--very friendly and personable.
Of the Trek actors I've met, I have to echo many posters here and say Shatner was the worst, but his ego is so friggin big I'm surprised con organizers can get him inside whatever convention centre he happens to be at.
In order from best to worst out of the Trek actors I've met:
Off topic, the coolest genre actor I've ever met was Michael Hogan (Colonel Tigh on nBSG). Awesome, awesome guy who loved posing for photo after photo (FREE photos, not the posed ones they charge for) and signing stuff (again with no charge) for my friends and I. Oh and then he got drunk with us at the bar.