Dr4g0n5h4d0w, here's the method I use. I'm sure myg0t is gonna flame me for sharing this with a noob, but its all about the raging, right? Ok this requires some quick timing and a decently fast computer.
1) Open a text editor (like Notepad) and type this in %0|%0 then goto File>Save as>change the Save As Type to All Files and then save it as Crash.bat and save it to somewhere easy to get to, like your desktop.
2) Open any Source game and join a server you want to crash.
3) This step is optional but it seems to help a lot (I'm not sure why yet though). Open up your console and type cl_cmdrate 2;cl_updaterate 2
4) Now when you're in the game you want to crash, wait til a new round starts and then IMMEDIATELY alt-tab and run the Crash.bat. If you were too slow it'll only lag you out, but with any luck it will have lagged the server and crashed it or lagged all players out.
Enjoy! I like to hack until they're going to ban me and then crash the server using this method. :cool: