There are only a few extra features in Ultimate that are useful for consumers. Most of the additional features in Ultimate are for IT Professionals.

-BitLocker Drive Encryption – As opposed to EFS, which uses file system level encryption, BitLocker uses full disk encryption.
-Ability to switch between 35 different languages instantly
-AppLocker – Ability to block software from running on the computer
-BranchCache – Allows for fast file access across a WAN
-Direct boot from VHD – Ability for a computer to boot from a VHD file with or without a host operating system
-DirectAccess – Keeps mobile users connected while on the go
-Virtual Desktop Infrastructure (VDI) enhancements

So even though Ultimate sounds great, it’s really not useful for the average consumer. Even to a degree, Professional also is not super useful for the average user. It’s probably best to get Home Premium and then upgrade to Professional or Ultimate if you ever need to.