Although gaming has been around for a good couple of decades longer, voice acting as an integral part of the medium only really came to prominence in the late 90s.
You have to remember: video games weren't thought of as anything close to 'cinematic experiences' until Metal Gear Solid proved they could feel like being in a playable movie. Hideo Kojima had been experimenting with more script-heavy, Hollywood-aping action across both prior Metal Gears and his 2D masterpiece, Snatcher, but it was 1998's Metal Gear Solid that gave us cutscenes shot like mini movies, proper silver screen acting performances and a composed soundtrack rather than a series of MIDI board blips and bloops.
It might all seem by-the-by now, but these were huge steps for a furtive entertainment industry to make - steps that we can see have bore fruit in every triple-A game shipping with the aforementioned components as standard.
All that said, which leading performances are the best? Which characters are gaming's finest, and which actors nailed their roles with such perfection we'll be talking about them for decades to come?