I have really fond memories of the first Forgotten Realms products as well, but I voted 3rd Edition/3.5 Edition.
I love the 3.5 rules and I own every FR book since 3rd editions release. Theres enough background material in the new books to last a lifetime no matter which part of the Realms you prefer.
Although I wasnt a fan of the ToT, I did read the novels and I did run the modules. As far as my gaming group goes, our campaigns never focused on the ToT past or present. Probably due to the fact that I havent used the Zhentarim much in my campaigns.
My opinions on some of the ToT stuff...
1) I hate Cyric as a deity (didnt like Bhaal either for that matter). Bane will always be around in my campaign, mostly supported by Cult-like cells until he returns to his former glory.
2) I like Kelemvor as a deity. IMO, we needed a deity like Wee Jas for FR. Gods of the Dead are normally stereotyped as evil. Myrkul didnt help matters there

. Myrkul is too cool to pass up though.
I definately kept him and in our current
Shackled City Campaign (based in FR of course) , Embril Aloustinai and Ike Iverson are really followers of Myrkul posing as clergy of Kelemvor. I gave them each the "Servant of the Fallen" feat from Lost Empires of Faerun.
3) Mystra is fine as is.
The rest of the realms are fine as they are with the exception of the super powered Elminster, Drizzt, etc. I kind of did away with them.