If truly anything is up for grabs, this seems pretty easy to me: the SNES era reboots of the core NES games, assuming those count as "retro revivals": Super Mario World, Super C, Castlevania IV, Megaman X. I think a case could be made for the next generation, too: Mario Cart 64, Super Mario World, Ocarina of Time, Star Fox 64, Symphony of the Night, Shining Force 3, the Shining in the Darkness sequel (name escapes me). I've heard good things about the Tell Tale Sam & Max, the Bionic Commando remake, and the recent Wolfenstein remake. I don't know whether the single player was any good, but Wolfenstein Enemy Territory was ludicrously great.
Actually. No. I think there's an easy answer, though not sure it fits the bill: Duke Nukem 3D.
Actually. No! Even better! The Sierra VGA remakes of the pre-VGA titles, especially QFG.
WAIT!
Might it be Day of the Tentacle as a revival of Maniac Mansion?
Or wait. Metal Gear Solid, perhaps?
Gah, the field is too crowded. It's impossible.
All I know for sure is that they used to be able to reinvigorate franchises really well.