Handbrake is my favorite for DVD to iPod/iPhone. Not sure about Zune.
http://handbrake.m0k.org/
Freeware, open source, GPL and it works well. It's extremely easy to use - just pull iPod or iPhone or anything else out of the drop-down box and hit convert. The quality is very good, although the filesizes are a bit bigger than I'd have expected. Runs at about a speed that's a third of real-time (1 hour encrypted in about 20 minutes) on my Core 2 Duo system. For some DVD's I've had issues ripping directly and have had to use DVD Decrypter.
I've also been using Videora for Divx to iPod/iPhone.
http://www.videora.com/en-us/Converter/iPod/
Also Freeware, also easy to use and fast.
And lastly there is MediaCoder which converts everything into everything else but doesn't seem to like my iPhone very much (converted movies don't work).
http://mediacoder.sourceforge.net/
Open source, GPL, and converts everything into everything else. But doesn't rip from DVDs.
Edit:
I saw this on Digg.com tonight:
http://lifehacker.com/software...-converters-316478.php
The top 10 free video rippers, encoders and converters. I was pleased to see everything that I mentioned above on the list.
