I was a long-term user of Firefox. Since it went under the name of 'Phoenix' (version 0.3) in fact. I have come to prefer Chrome these days though. I'll sometimes use IE9 because I think this is a pretty good browser as well. It's better regarding security than earlier versions were.
Some people worry about privacy issues with Google Chrome ..and Google in general come to that. If that is a worry, there are steps that can be taken. Use a different search engine and alter some settings in Chrome.
All in all Google Chrome is a good browser in my opinion. It includes Flash Player (this updates automatically as soon as new versions of Flash are released). It also incorporates a PDF reader. Chrome can even be set to be the default PDF reader for PDF files that are stored on your computer. No need to use Adobe Reader, Foxit Reader or other PDF readers if Google Chrome is installed. Plenty of extensions are available for Chrome too.
Chrome has a sandboxed structure. This can be a protection against drive-by malware (malware picked up inadvertently while browsing) getting onto the system.
About Chrome's sandbox:http://dev.chromium.org/developers/design-documents/sandbox/Sandbox-FAQ