The coolest project I ever worked on wasn't programming per second, though it involved a bit of scripting. The company I worked for had an FTP over TLS backup solution and it was put together with glue and paperclips by a guy that hadn't the slightest idea what he was doing. In order to conform with the insurance, data had to be encrypted. I setup a raid-ed server with full disk encryption on the raid volume that fetched the key over the network at boot from another secure server. I wrote a series of scripts for provisioning users and so on. The backup connections was sftp using a ssh tunnel, the users were chrooted to their own home directories, and were unable to open shells. The system was 100x more robust and secure than the original. I set it up on short notice and received absolutely no recognition for saving the company's ass, but it was definitely a fun project.