If you are impressed with the the clock of HTC Sense 4.0 seen on HTC One X. Then you can use Fancy Widget, they have a theme that is similar to HTC One X clock.
See the screenshot of Google Nexus One with Fancy Widget.
How to install Fancy Widget skin
Extract H7CSlateClock.rar and copy H7CSlateClock folder in Android > data > fancywidgets > clockskins. To browse this location, you can use your file manager.
You can download Fancy Widget Pro from here.