Rivers is #5 all time in passing yards (between Favre and Marino)
He's also #5 in all time pass TDs (between Favre and Marino)
If he retires this year, he'll be #4 or #5 among all-time QB rating (for those with complete careers, depending if Brees has finished his career or not), just behind Peyton Manning and ahead of Kurt Warner and Joe Montana
He'll be #4 (among completed careers) in adjusted net yards/attempt. The three behind him are Steve Young, Kurt Warner and Joe Montana.
#6 in TD/INT ratio
1. Kaepernick (who never had a decline phase for other reasons)
2. Steve Young
3. Peyton Manning
4. Tony Romo
5. Andrew Luck (again, missed all his decline phase)
6. Rivers
7. McNabb
8. Montana
#12 all time in Career Approximate Value (#4 among QBs behind Brady, Manning, Brees and ahead of Marino and Elway)