A newbie needing help with .avi file quality

I have quite a large number of .avi files,

Movies, TV shows, anime, etc.

I recently started burning them on DVDs so I can watch them on my tele.

Is there any way to improve the quality of these files when I burn them onto DVDs, as they don't look any good on the TV. Very Grainy, even DVDRIPS

I use ConvertX to DVD to burn my DVDs

Thanks alot to anyone who can help me

 

Do you use Fast Encoding(poorer quality) or Slow, Higher Quality?

 

Should he also slow down the burn speed

 

I use the default setting, which is medium.

Another thing is that The dvd burned as widesreen, beacuse the avi file I had was widescreen.

My TV however is a crt and is not widescreen.

Is there any way to fix this???

Thanks