For my personal machines I've been using Veeam's free version. It's not as full featured as what I'd like (I have it set for nightly backups), but it seems to do the job alright. It offers to make a bootable flash drive for you at installation to make full restoration easier. I have it backing up over SMB to a FreeNAS box, but it doesn't look like the backup images are easily readable (the look to be some Veeam-specific format, but I didn't look to hard at them).