Long been a favorite on BlackBerry, BeWeather is a drop dead gorgeous weather app for Android. It gets its data from Weather Underground and wraps it in a nice package with a ton of options.
There's detailed forecasts, 11 different widgets in 6 different sizes, temperature notification in the status bar, radar and satellite maps and a TON TON TON of customization options where you can change the icons, fonts and colors of the look of the app. It's pretty much the new best weather app around. [Android Market via Android Central]