Chrome is ridiculously awesome IMO.
Each tab (and addon) loads independently within the OS, allowing you to kill one pesky subprocess without bringing down the whole browser. This also means one tab can't hijack another tab and steal information as easily.
Because each tab is loaded independently I can drag off a single tab into a new window without reloading the page. I can also drag tabs around into a different order. Using two monitors and win 7 (Aero Snap) that means with one click and a move of the mouse I can move a tab off, into another window, and maximize it with ease.
You can't do that in firefox, because when you drag a tab off it'll reload the tab. You can also google search directly from the URL bar (You can in Firefox, but you have to know what you're doing) as well as setup search terms, such as typing in wiki blahblah will automatically search wikipedia.com for blahblah and bring up that page. You can do this in firefox, as well, but it's still nifty.
It also has first party built in addon and bookmark sync. Being a person who uses 3 computers often, this is handy for me. (Netbook, main PC, and HTPC for couch browsing/netflix/digital backups of DVDs to .iso format)
Also, all of the best firefox addons (adblock, e-mail notifiers, fasterfox (or is it fastestfox?) etc.) have Chrome versions.