In the picture you posted, your TV (against the window) performs better than the display in the foreground by 50-90ms, not the other way around. haha I thought the problem was lag on your TV. The thread probably could have ended right there...
I have read that some Onkyo AVRs used to have terrible latency (lag). Have you tried connecting your laptop directly to your TV using HDMI? How about VGA? You could always send the video signal to the TV using VGA and the audio signal to your AVR using HDMI and bypass any video processing lag introduced by the Onkyo. This is easy to do in Windows 7, I've done it with my laptop before.
Using "game mode" on the TV should be sufficient, but make sure all extra processing is turned off. This include things like "active contrast" or "clear motion CMR" or whatever other crap the display may use. Since it is a 120Hz panel, it probably uses some form of "frame creation" or interpolation. Turn that off, too. Also make sure that you have the latest firmware for the TV from Samsung.
Also, I'm confused by your comment:
"I used to use a older desktop for gaming on my tv with the same HT setup hooked up hdmi and I know how bad the input lag is for a desktop setup to the tv, so that isn't an option for my tv."
Desktops and laptops can have equally good or equally poor latency, so I'm not sure where you get the idea that desktops have worse lag than laptops (it's probably the opposite in many cases). If you want the best experience for online gaming, you get an old CRT, turn off all extra processing in the drivers (including VSYNC), and only use a wired ethernet connection (no WiFi).