At the moment Chrome is the best browser on the market. It uses the fastest rendering engine (Webkit) in combination with a very fast javascript engine. But my most favored feature is not the speed, it's the extension system. Here I will post a few I use on a daily basis.
Delicious Bookmarks Extension
Sync your bookmarks with your delicious account. Not perfect, but a good start. Hopefully this extension soon gets the all features of the firefox version.
AdThwart
The best ad blocker for chrome.
RSS Subscription Extension
Chrome can't handle rss feeds, this extension fixes that. Click and subscribe in your google reader.
Google Quick Scroll
Highlights the text you searched for in pages you opened after clicking in the google result list.
Vimium
Vim-Mode for Chrome. If you hate to use your mouse.
Downloads
Add a button to the toolbar for opening the download page.
If you want to keep track of all chrome extensions I use, you can subscribe to my links on Delicious tagged as Chrome.
Nightly builds
At the moment I am using the nightly builds of chrome to get the newest features and the best speed. I hated the manual installation process, so I created a little shell script for my mac. You can get it in my github repository: chromium-install.