This is one of the worst sights in Minecraft. Not being able to connect to a server can be heart breaking. Before changing anything on your client side it is best to check help.mojang.com to see if everything is running smoothly.
If Mojang is not having issues then check our server at www.creepercountry.com. If arrow in the right hand corner is green then the server is working properly. However if the arrow is red the server is down. Occasionally the website and the server are not in sync so it is recomended to check the shoutbox and announcements for further information.
If the server is up and running then the issue is most likely client side. Suggestions for fixing issues on client side include deleting your .bin folder, downloading your Minecraft launcher again, checking to see the server IP is correct and restarting your modem or router.