The end quality does not always depend upon the software. There are many factors. The bitrate you are encoding, quality of media, hardware, software, all factor in. In general, quality costs money. Free stuff will do a decent job, but it isn't professional. FAVC is pretty good for the free stuff, as is Convertx2dvd. If you want professional, you need a quality Encoder which is capable of multi pass encoding.

You need to figure out what you want, what you can live with, and then do some reading, and see which softwares might fit the bill. Then come back and ask people their opinions (which will be many, and be varied)