I have lots of signed books, but most I have picked up elsewhere...not at signings. Those that are signed personally to me, I usually have some connection to the author that I either get them signed before or after or just hanging around with him at the event, so I'm usually not standing around in line.
One of the few times I remember standing in line was when Bruce Bennett (Herman Brix), then in his nineties, was at the Ray Court Hollywood Collectors Show. I stood in line for him to sign his bio, PLEASE DON'T CALL ME TARZAN (and it was one of the longest lines ever there). He signed to me both as Herman Brix and Bruce Bennett, the author of the bio...Mike Chapman inscribed it as well...and Danton Burroughs, Edgar Rice Burroughs' grandson who wrote the forward and is an acquaintance, also inscribed it...so it's triple signed.
Usually when I'm with Harlan Ellison, I'll get him to sign another one of his books to me...I don't like inundate him, but I've got a fair bunch of great inscriptions from him to me on his books.
But most of the guys I collect are dead guys...but I've got signed Sabatinis, Talbot Mundys, Burroughs, P.C. Wren (wrote Beau Geste), Etc. Sabatini has the most interesting signature...teeney-tiny. The man must have had no ego at all.
I'd like to meet William Goldman someday and have him signed my near-mint PRINCESS BRIDE and also TEMPLE OF GOLD.