At work I use a macbook, and to keep a good separation I use firefox for "personal browsing" and safari for all work-related browsing and logins.
Firefox, with tree style tab, might not be the best browser but it's good enough for me. I just wish I could trust Mozilla to make good decisions these days. Pushing addons, pocket, etc, etc, it's all a bit worrying. But I guess back in the day I paid for my name to be included in the NYT Firefox advert and I've stuck with them since then.