.com vs other top level domains

I have found the perfect domain name that I want but of course, it is taken for the .COM_ version. I keep hearing conflicting stuff on this, so I thought I would ask it here. Should I even mess with .info_ or .org_ domain? Or just choose some variation of my perfect name to get a .com_ domain.

Also, what kind of domain name hacks do you like to get .com_? For instance, say you want puppyfood.com_ and it is taken, so you instead get puppyfoodHQ.com_

Please ignore the underscores. Had to use them because of the noob restrictions for newer accounts.