Do you want to record your XBox gameplay on the XBox or on the iMac?
Recording with Hauppauge HD PVR
Elgato Video Capture device
In the end, you need a capture card connected via USB or if you have a miniDV camcorder with video input, you could loop the video through the camcorder or record to it.
Then use iMovie to edit the footage.
Btw, your signature uses the capital "I" for the i-devices, though Apple uses a lower case "i". Examples: iMac, iPod, iPhone, iPad
want to record my xbox gameplay then get it on my imac and edit it there..need to know what software to use to edit the footage and add effects n music to then put it on youtube ?
so i need to know what software is the best to use to edit video ???
iMovie, as already mentioned. Or if you want to spend some money, either get Final Cut Express or Premiere Elements. And if you want to spend some more money, or maybe are a student or teacher, you can get academic/student versions of After Effects (for that effect work) and/or Adobe Premiere or even Avid Media Composer.
You can also take a look at Final Cut Studio, but all the applications I mentioned, besides FCE and iMovie, might be a bot overkill for editing XBox footage.
so what do you think would be best to do ?