comprehensive-google-map-plugin

There's a fork of this plugin, called Slick Google Map, which removes the reminders added by the current maintainer encouraging you to convert to a premium service. Thank goodness for open source and the GPL!

Must buy the premium version to get a usable plugin.

Easy to use, extremely configurable and makes any google map look great on your website. You can check out my website to see how I am using it. If there was two features I would love added to it, they would be: 1. The ability to add your own customized routes to the maps. 2. If Google hasn't got a correct location for an address (this is normal in Ireland because the guys who built this country decided that addresses aren't really important), and so you need to use long/lat coordinates, that you could create a custom address so that when someone mouses over the map, they don't see the long/lat coordinates but the actual address of the location.