I've tried at least a dozen, and this is my favorite weather app. It has a gorgeous interface and really packs a lot of info into a small area.

Alternatively, I can click on the link in my dock and load a custom www.wunderground.com page in Safari, which has, at only a click or two away, more weather and radar info than Wx can shake a stick at. It's not as pretty as Wx, and the information isn't displayed quite as efficiently as in Wx, but it loads just as fast and Safari is rock solid and always updated to work with the latest OS X release.

All else being equal, I'd probably opt for Wx, but all else is about $17 in Safari's favor. Wx is a wonderful app, but IMO it's trying to fill a niche that isn't there.