Mac's and Video Editing

Hi, I’ve started to create Videos (Captureing editing etc). And i was wondering how good a Mac is at it. And if so what kinda specs should i have on my Mac for it to be a kick-ass Video Making machine... Well infact. What should be a great Mac specs? Fast, powerful number crunching Video creating machine.

Also- What software is the best for video editing for the Mac? And also, how good is Vegas video, and 3dstudiomax- for Windows computers?