I don't think any of them was innovative at all? Now which had an impact on the industry is a different thing, and not easily measurable.
Tomb Raider did third person action, adventure and puzzle solving long before RE4, and Gears wasn't the first to add a cover mechanic to the formula. It was probably inspired by stealth games and made it more about action. Kill Switch on PS2 was similar (not great though).
It was? Are we talking about RE4 itself, or just about what the Wii did for the game? I don't see anything new other than that port. Plenty of action games had a similar third person style. Ok so Tomb Raider feels different because the camera's further away and your character more agile, big deal. What about Splinter Cell then? Shooting mechanics are very similar, you move slowly with an over the shoulder zoomed in camera etc. There's probably other games that did it.
Well, it sold over 1 million copies (not bad for a port that was already on 2 platforms, including the console with the largest install base) and was hailed as the best version of the game by critics, so I'd say people cared. If you didn't mean that port, what was the new way to play then?
As for other third person games not being brought up much, it just shows how short memory gamers have, and how it's really the mainstream (casual as they like calling it nowadays) that apparently decides what's innovative and what isn't, since if everyone isn't talking about it I guess it can't be innovative, while when everyone talks about it, it's innovative even if it's been done countless times before. Meh.