PC-BSD 64 bit
I visited the PC-BSD website today and I downloaded the Oracle VM Virtualbox 64 bit disk image. I decompressed it and I created a new 64 bit guest virtual machine based off of FreeBSD 64 bit for PC-BSD 9.1 64 bit Isotope Edition. I logged into the pcbsd user using pcbsd as the password and I performed a software update. PC-BSD 9.1 64 bit Isotope Edition is pretty nice. It uses KDE as the default desktop environment. There is the AppCafe which is similar to the Ubuntu Software Center. PC-BSD 9.1 offers limited support for TrueCrypt 7.1a 64 bit. The problem is that it uses FUSE which is not well supported in PC-BSD or any BSD UNIX. I find it to be very reliable and stable and it consumes very little resources. It is particularly fast and secure right out of the box. I am going to play around with PC-BSD 9.1 64 bit Isotope Edition more tomorrow, but this looks like a good BSD UNIX operating system.
I have a System76 Lemur Ultra (lemu4) and I will stick with Ubuntu 64 bit GNU/Linux as my default operating system of choice, but PC-BSD 64 bit might be another alternative that I might enjoy using.
I recommend that other Ubuntu users consider PC-BSD 9.1 64 bit Isotope Edition if you want to learn more about BSD UNIX. In my opinion, BSD UNIX rocks and it has certain advantages over GNU/Linux. It is a complete operating system and everything is designed to work seamlessly as a whole.
I may wind up using PC-BSD 9.1 64 bit Isotope Edition more frequently, but some critical software and hardware devices don't work with it such as LastPass Premium, TrueCrypt 7.1a 64 bit, and Yubico Yubi Keys. This is why I will stick with Ubuntu 12.04 64 bit LTS because everything is guaranteed to work right out of the box.