About the time the 1st map pack came out, I noticed suddenly one day not being able to find lobbies with <50ms ping nearly as easily as before. Before, I'd start up and I'd find 18-25 games easily that were in the <50ms category. Now when I search, most of the time I find zero games at <50ms and sometimes even zero at <65ms. 
 
Has anybody else noticed this? Connection quality is very important when trying to be competitive, at least for me anyhow and hate it when variables are unfair.
I have a feeling this began when the hacks started invading the game...

make sure your NAT is open. Other then that theres not a whole lot you can do.

I very rarely get lobbie with a ping of under 65 in MW2. I recently moved to another town about 1.5 hours away and I still get the same ping, same internet provider though. I have even tried removing the router and going from the xbox straight to the modem and that didn't help the ping at all. Speed test shows my ping at a 50 - 60 generally.

Do you have the map packs? The map packs split the playerbase, so that might be a reason regardless of whether or not you have bought any. I didn't buy any of them and I sometimes have a harder time finding games, but if Im patient I can normally make it into a 4 bar game (or get host, even better).

I also bypass my router completely and go directly from the xbox to the modem. NAT is Open. 
I bought the 1st map pack as soon as it came out...no difference. 
 
My friend has a jtag hack or whatever it's called and anytime he wants to search for games, he can't hop into rooms- He has to wait for players to join his room as the game automagically wants him to be the host. I haven't a clue how all that jtag stuff works, but is it possible that this is part of the hack, that it gives host advantage?