I've said this various times, but I'll say it again:
Safari: For my main account on PC, for uploading purposes, and for fanart hunting. Default browser since Mac.
Firefox: Used for manga reading, downloading, browsing PC on an alt. (Sewaddle, at the moment), video watching, LJ RPing, etc. Despite its many uses I use Safari more o3o
Chrome: For MAL, a flash game, sometimes PC on another alt., the occasional video watching and the occasional fanart hunting. It's the only browser of mine that doesn't seem to randomly crash.