Here are all the ones I had seen prior to watching LOST for the very first time
- Ben (Michael Emerson) and Miles (Ken Leung) in Saw 1
- Juliet (Elizabeth Mitchell) in the Santa Clause movies
- Charlie (Dominic Monaghan) in the Lord of the Rings movies
- Kate (Evangeline Lilly) and Charles Widmore (Alan Dale) in the MCU
- Ana Lucia (Michelle Rodriguez) in Fast and Furious
- Mr Eko (Adewale Akinnuoye-Agbaje) in Game of thrones
- Abaddon (Lance Reddick) in the John Wick movies
- Kelvin (Clancy Brown) in Shawshank Redemption and I heard him because he was Mr Krabs
- I heard Mikhail (Andrew Divoff) in Black Ops 1 as Kravchenko
- Bernard (Sam Anderson) and George (Fisher Stevens) in Friends
-Paulo (Rodrigo Santoro) in Love Actually
- Mike Walton (Michael Cudlitz) and the mechanic in the flash sideways (Jeff Kober) in The Walking Dead
I didn't know I had seen some of these actors before until I found out or rewatched the things I saw them in.