I am a big fan of the FR pantheons, and a bunch of that is the variety of specialty priests from
Forgotten Realms Adventures on and lore from the fantastic 2e FR trilogy of god books. A bunch of that interesting mythic lore is their doings in the Time of Troubles, so I have a fondness for post 1e FR.
1e is pretty fantastic though with the core FR stuff done out (red wizards, zhentarim, drow, pirates, dracoliches, etc.) and does not have the Time of Troubles killing off a bunch of the cooler gods or unleashing wild and dead magic zones.
2e was a bit hobbled by TSR's then product morality code for villains not succeeding so they were much less a competent threat in a number of ways in a lot of adventures. 3e brought it back to a tone of bad guys and bad guy groups being big threats generally outnumbering the forces of good. The
3e Campaign Setting core book is also fairly fantastic for an all in one coverage of the core setting and stuff, with a cool development of Red Wizard enclaves for if you are doing a game with buying magic items (3e, pathfinder, etc.) and some developments I was not that big on (Netheril shade empire returning).
4e was for fresh starting the FR by jumping the timeline and allowing lots of dragonborn and tieflings and cutting down the lore hugely through another apocalypse wiping lots of stuff out and introducing new stuff.
5e is the most recent, mostly resetting a bunch of the flavor of 1e-3e but advancing the timeline again so half the NPCs of that era are long dead but you can use lots of the lore.