Ping Problem

[iou]

I share internet with two person one of them downloads and uploads things the other person plays Combat Arms(a pretty dumb game) so this makes my ping to jumps high

so this means that i'm fucked 

Downloading and uploading causes major ping spikes. However, it's the uploading that causes the most interruptions.

If he is downloading by torrents, tell him to set the max upload speed to 5kb/s in the torrent software hes using. Combat Arms is a game, it both downloads and uploads, just like every online game. But it takes very low bandwidth, so it shouldn't matter if hes playing or not.

Simplified solution.
Smack em' in the face and unplug their internet cables.