Mannahnin
Scion of Murgen (He/Him)
Seems pretty solid.Golden Age 1979-84
From the Egbert Explosion to the ET Collapse (heh... little Atari reference for ya). In other words, the explosion of D&D into mass popularity (and fad status) that followed the media coverage of James Dallas Egbert III that lead to the mainstreaming of D&D (and other RPGs) in the fall of 1979, all the way through the over-expansion and pulling back in 1984 at TSR (which .... happened to mirror the similar over-expansion and collapse of the Atari 2600 and related video game consoles... maybe there's an essay in that somewhere).
Silver Age 2000-07
The release of 3e, the release of the OGL, the "return" of D&D as well as the incredible rise of people who were disaffected and started branching out to create new & different ways to game- either by seeking a return to the past (the creation of the OSR / retroclone movement) or mapping out different ways to game (the Forge and numerous new ways to indie game). The starting point of the silver age is easy- 2000 (release of 3e and the OGL). The ending point is ... harder. Is it ... 2003 (the release of 3.5e)? Naw.
2004? Castles & Crusades .... naw. Not OSR enough.
2006? When certain quotes appeared on the Forge? Mmm... closer. We also have OSRIC released on that date as well as BFRPG. Also also? Dread!
2007? The announcement of 4e (which lead to PF, etc.)? Maybe.
2010? Apocalypse World (PbTA)? Seems a little late and would bleed into the Bronze Age.
I'll peg it at 2007. We already have a lot of the underlying intellectual foment in terms of open licenses, new types of games, and OSR that will continue to be developed, and the 4e announcement (along with no open license) effectively gives it rocket fuel- but sticks a stake in the D&D part of it, effectively bifurcating the market ... for now.
Bronze Age 2016-23(?)
Finally, there is the bronze age. I thought about this a lot. I can't put it at the release of the PHB. But in 2016, we have the release of the OGL. The first season of Stranger Things aired on Netflix. Critical Role was beginning to gain momentum (although it wasn't what we think of it yet). 5e was back to being ... A THING. And we saw the publication of really popular materials for 5e- Curse of Strahd, VGTM. In addition, the indie market was beginning to hit on all cylinders- you had Blades in the Dark had early access availability in 2016 (with physical product in 2017) and storytelling games like Ten Candles were also becoming more mainstream.
So I'm going with 2016, although that's an inexact science.
I'm wrangling over and trying to figure out how to map the OSR explosion onto it.
The seminal discussions and ramp-up conform pretty closely to your silver age, but the blogosphere explosion started in 2007-2008. Delta's D&D Hotspot in March 2007, Sham's Grog & Blog Feb 2008, Grognardia Mar 2008, Monsters & Manuals May 2008, Michael Curtis' Society of Torch, Pole & Rope (whence sprang Stonehell) Aug 2008, Bat in the Attic Oct 2008, etc. (Tenfootpole didn't launch until 2011, though IIRC Bryce was posting reviews on forums earlier, Goblin Punch not until 2012). The One Page Dungeon Contest started in 2009.
For a while there was definitely an OSR Golden Age in which discussion and creation just EXPLODED, and it was almost all free stuff, before it got commercialized. I didn't even participate in the Google+ part of it, but that was another enormous collaborative creative space, featuring near-constant gaming and idea sharing.
In terms of available products (many of them still free!) and systems we're clearly still in a golden age for this area of gaming. And high production values have become much more common, but that's been enabled by the commercialization of so much of it.