general use (most stuff): Firefox
random browsing (webcomics, random searches): Chrome
workrelated site checking: Opera
for logging stuff in a crappy built web app: IE 6.0 (lol)
Chrome is great if you like to get datamined by our Eternal and Benevolent Google Overlords. SRWare Iron is a privacy-friendly, Chrome-based, Chrome-flavored Chrome alternative. No additives, preservatives, or artificial flavorings.
That said, I've been using Firefox for years, and have customized and tuned the thing into being perfectly suited to my needs, so I rarely use anything else.