Paarthurnax is a very good example of long form Dovahzul. The greybeards are a good example of mixed form although I don't think either fully sticks to one. Long form vs mixed form is a way of describing the some of the vowel differences between actors. It is currently unknown which is correct so both are valid.

I would include Odahviing and Alduin as well; they're also good references because they show different vocabulary and words with personal pronoun suffixes.