To me, variety is the most impressive. Dr Duran Duran said he's got 500 diff Seitzers? If true, that might be most impressive. Seitzer's last year was in 1997 so his last card year was probably '98. To get to 500 diff means he's likely got a ton of oddball stuff and rare-ish/numbered parallels and inserts.
My guy is Rusty Greer. Unfortunately my pick is poor not because Rusty's career was less than outstanding and came to an early end, but because when his good cards were filtering through ebay there were two or three bigger collectors on there with bigger wallets. Still I have some cool ones like a 1997 Topps Gold Label 1/1 and a strange oversized 1998 Fleer Classic 63 numbered 00 of 63.
“Most men lead lives of quiet desperation and go to the grave with the song still in them.” --Henry David Thoreau