Specifically CoD4 and Black Ops. When I play directly plugged into my modem (my modem has two ethernet ports), it seems like a majority of the time I am on a 2 bar connection (out of the average 3-4 bar). I'm usually not lagging during movement such as running, but everything else seems to be delayed. For example, I click LB to throw a stun grenade and it takes an extra second to register. I also seem to get extremely severe bullet lag. I'll get on a decent connection maybe 1 out of 20 games, but usually I'm on a 2 bar suffering from ridiculous delay and latency. If I'm plugged into my wireless router instead of my modem, I get the same issues but worse. Plus it takes me about 2 minutes to find a game (vs the normal 5-20 seconds). I doubt it's a problem with host selection because my friends I party up with in the area don't have the problems I have in the games.
I've reset my modem and router tons of times, there isnt anyone else on my network doing anything, my NAT type is open, I have really good internet speed, I've changed ethernet cables 3 or 4 times, I've tried different ethernet ports on my modem and router, I've tried nearly everything and nothing is reducing this lag.
What could be causing it and what could I do to fix it?