I probably couldn't make a comprehensive list of everything that was good about the GSOT but I don't think any other fans have ever had it better. From breaking that fucking 0-17 streak against the 49ers to the incredible opening salvo in the playoffs against Minnesota to Proehl's catch to Bruce's catch it was a constant roller coaster ride of fun and excitement that usually netted a Rams win.
I don't see how it could ever be better than 1999 for a Rams fan. They may win it all again but it'll never top that season the Rams had.