As we all know there have been lag complaints.
I AM NOT HERE TO TALK TRASH ABOUT SERVERS OR GEARS ONLINE PLAY. DO NOT DO THAT FOR THIS THREAD PLEASE.
I found this short article from PC magazine and thought I would share it with the community.
If you are getting disconnected from xbox LIVE suddenly or find yourself freezing online (and sometimes slow internet connection) give this a try.
There could be a number of reasons for slow connection such as a router problem, modem problem, etc...

1) If you use WiFi, move your PC into the same room as your router and use an Ethernet connection. If the problem goes away, it's a WiFi problem, although you still won't know if it's the router or the PC.

2) Try replacing one or more of the cables involved. If you replace an expensive router and then discover the problem is a $2 telephone cable, you'll hate yourself in the morning.

3) Borrow another laptop or invite a friend to work at your home for a couple of days. If you have the problem and they don't, the problem is with your PC.

4) Bypass the router and connect the modem directly to your PC. If the problem reoccurs, the problem is either with the modem or the connection. But remember, not using a router is inherently dangerous, so go back to the router as soon as you've identified the problem.

And if the problem doesn't go away after all of these tests, it's your ISP's fault, even if they insist it isn't.

I know this is related to a PC topic, but a friend of mine who complained constantly about lag tried this out and it was his cat 5 cable. He experiences lag on VERY RARE occasions now.