So now that you’ve installed and setup Growl, you might want to download some additional styles, if none of the included ones really catch your eye. Or, if you’ve been using the same one for ages (guilty) and want to mix it up a bit.
2020 Update: Growl is something you’ll probably only want to use if you’re running a version of macOS (OS X) earlier than 10.6. The vast majority of the features available in Growl are now built into macOS via the Notifications. This guide remains online for those of you running 10.6 or earlier and still want to use Growl.
The ‘official’ Growl styles site, http://growl.info/styles, has (at this time) 40+ additional styles for you to download.
The GrowlHUD style is elegant and minimal – I may end out using it full-time if I get bored of the iPhone style.
The iOS Growl style is the one I’m currently using.
Adium Growl Style 2 was based on MSN GrowlStyle, but without the ugly MSN icon. Though you probably won’t want to use it as the system-wide default Growl style, it makes an excellent style for Adium notifications.
Another style that you may not want to use system wide, GotMail makes for an excellent mail notification.
The Glass Candy Growl styles aren’t entirely my taste – but they might be perfect for you.