I've been using Chrome more and more over the last few months. It's been a battle of speed vs. features for me. When FF is loaded up with a dozen extensions, its features clearly outstrip Chrome, but it slips in speed.
I stripped out a bunch of my extensions, and I'm down to these "essentials":
- AdBlock Plus Ads have grown increasingly obnoxious on the internet, this is a good way to take back some control.
- Delicious Bookmarks I bookmark anything on the internet I might want to reference later. It has become easier to build a delicious collection of personal links than to store all of those in one browser.
- Download Statusbar The built-in download window for FF is kinda obnoxious, because it resolves something via a popup that could otherwise be resolved in the same window. Chrome defaults to providing download info in a statusbar, but allows you to pop out a window for more info if you choose. The Google statusbar could still be more informative (speed info and pause/restart/multithreading options would be ideal).
- Google Gears Lets me use Google Docs offline. No doubt this will become better as more webapps use this to allow offline access. No doubt Google will include support for this extension in Chrome very quickly.
- Linkification Converts text links into a clickable links. Saves me about a dozen copy/pastes every month.
- OpenDownload Restores the "open when complete" option to the FF download dialog, a feature that was stripped from all users sometime during FF's paternalistic security freakout.
- PDF Download Keeps you from accidentally clicking through to a PDF link and losing control of your browser for a minute while it loads. Chrome's architecture should make this less of an issue, as each tab is handled in a separate process.
- Repagination Lets you view multi-part articles in one giant page. This is currently dead, but is very handy for those obnoxious sites that put out 25 part articles with a short blurb and photo on each page. Currently dead, and needs some enterprising developer to make a version that supports 3.0.4.
- Tab Mix Plus Includes tab features that should probably be included in FF by default, like an "undo" for recently closed tabs.
- Ubiquity An addon by Moz devs that allows quick interaction with website APIs, and stands to completely revolutionize browsing.