I use e.ggtimer.com regularly as my egg timer. This site follows google style of minimal interface with just enough options to get you going.
The most innovative feature is having special timers. Timers like the Pomodoro timer(set by http://e.ggtimer.com/pomodoro) is a very thoughtful addition. I hope they add more such special timers.
The use of the URL or the address to set the countdown timer is also cool. It may not be so intuitive to the layman, but still makes great feature and is a unique use of the url/address bar.
So visit e.ggtimer.com and start using it.