Mainly I know him for his voice work. But I've also seen him in a few live action roles... I always remember his face and voice, but I just don't generally remember what I've seen him in. Which is what makes IMDb so useful! There's The Blues Brothers; and Austin Powers; and an episode of The 4400; and an episode of Star Trek: Deep Space Nine; and an episode of Ned's Declassified School Survival Guide; and well... IMDb lists guest spots on lots of shows where I'm sure I've seen him, but don't remember him so well, like I said...
I know him from Jurassic Park, Merlin, Bicentennial Man, Wimbledon, The Triangle, and voice work in Legend of the Guardians: The Owls of Ga'Hoole.
Nelson, Craig T.
I know him from Coach; and The Fire Next Time; and Parenthood; and Poltergeist; and voice work in The Incredibles.
I know him from Adventures in Babysitting; and a few eps of Designing Women; and Bull; and a small role in Fireflies in the Garden; and a minor role in Switching Channels; and and some voice work.
I know him from Batman; and The Shining; and Something's Gotta Give; and Mars Attacks!; and The Little Shop of Horrors; and Chinatown. Not sure if I've seen him in anything else, but of course I should, eventually.
I know him from Underworld; and The Hitchhiker's Guide to the Galaxy; and Pirates of the Caribbean: Dead Man's Chest (and At World's End); and Harry Potter and the Deathly Hallows, part 1; and Total Recall; and The Limehouse Golem; and Ordeal by Innocence; and voice work in Astro Boy; and Rango.
First and foremost, obviously, he is Star Trek's Spock. And um... well I'm sure I've seen him in some other stuff, unfortunately nothing quite so memorable... Oh, I do remember hearing him on the radio once in a remake of War of the Worlds, that was cool... And I like his songs "The Ballad of Bilbo Baggins" and "Highly Illogical." Also, he voiced Mr. Moundshroud in The Hallowen Tree; and General Konrad on Invasion America; and the Zarn in the Land of the Lost movie; and Kashekim in Atlantis: The Lost Empire.
I guess I saw him in The Return of the King. And I saw a bit of Fringe, but I stopped watching after a few eps. (I later regretted that, and I'd really like to watch the whole series, someday.) I know him better from Sleepy Hollow; and season four of Elementary; and a few eps of Salvation.
Cliff on Veronica Mars, Gordy on Ned's Declassified School Survival Guide, Mr. Turner in Grow Up, Timmy Turner, Johnny Frost on a couple eps of iZombie, and various voice work.
I know him from Stand By Me; and My Secret Identity; and Sliders; and Scream 2; and Joe's Apartment; and Can't Hardly Wait; and a trifling role in The New Guy; and Jerry Maguire; and Mockingbird Lane; and the Veronica Mars movie; and a couple eps of Scream Queens.
O'Connor, Kevin J.
I know him from Deep Rising; and The Mummy; and The Others; and Van Helsing.
I know him mainly for voice work, but as far as live-action stuff goes, there's
a minor role in Good Omens; and an episode of The Good Place; and maybe some things I've forgotten (or not). I'm sure there's other live-action stuff I'd like to see (such as "Parks & Rec").
I know him from Heroes; and Hawaii Five-0; and minor roles in Get Smart; and Austin Powers in Goldmember; and Along Came Polly.
I know him from Bram Stoker's Dracula; and Leon: The Professional; and The Fifth Element; and Lost in Space; and Harry Potter and the Prisoner of Azkaban; and Batman Begins (and its sequels); and The Book of Eli; and Red Riding Hood; and he voiced Shen in Kung Fu Panda 2.
I know him from Psych; and Galavant; and a couple episodes of Supernatural; and a memorable ep of Lucifer; and an ep of Escape!; and an ep of Downward Dog.
I know him from Millennium; and Lost; and an ep of Masters of Science Fiction; and The Rocketeer; and Silver Bullet; and an ep of Star Trek: The Next Generation; and The Cutting Edge; and a small role in The X-Files: Fight the Future; and Emergence.