AVS Video Converter 6. I've had this program for 6 months now and love it. Very easy to use and you can use it to convert to any Format you like....3gp, MP4, DVD, AVI, MPEG, MOV, FLASH. Hasn't let me down yet!
I use Xilisoft Video Converter Ultimate (see link in my signature)
verry easy to use, ability to put subs in it and to watermark it (wich I do because someone on another forum accused me once of putting his movies up for download)
I use DVDVideoSoft. I used it with my iPhone and all the videos work perfectly with my Bold. I use the Video to iPhone converter that it comes with and I put it on the highest setting.
I use 3gp format as the file size is smaller and quality isn't too bad. There a free software converter I use called ABC 3GP Converter. Download free from DVD Copy Software, Free 3GP Converter, Video Convert Software.
Normally ripping from DVD I use MagicDVDRipper from Yasasoft. Its simple to use and I have a crack for it which I'm willing to share. PM me.
I would recommended using one of the specific converters for blackberrys from videora. Just search the Videora webiste and you will find the specific converter for your blackberry.