Ok, So I was one of millions who could not play at all since the patch, got every error in the book! This morning at 5am PST I started the game, pressed X to start online and everything worked, did the first race, drug run and bought clothes with other players. I previously had configured my router and this is what I did, maybe it can help others.
Use the following link to find your router and settings for your console, I did this part as "Single" port forwarding.
http://portforward.com/english/routers/port_forwarding/routerindex.htm
The specific ports for GTA V Online are as follow for PS3, not sure fi they are the same for XBOX:
TCP 80, UDP 88, TCP & UDP (both) 3074, TCP & UDP (both) 53, UDP 3064, TCP & UDP (both) 1795, TCP & UDP (both) 1745.
Make sure you set all of these to active and single out your consoles specific IP. I did these as Port "Range" Forwarding.
I also Activated the "DMZ" for my consoles specific IP.
Last but not least reset your router, if you don't have the option in the admin site than you must do it manually.
Good Luck!