I like
Dorothy as long as it is prn. with three syllables. Where I live it tends to be said "Dor-thy," which is awful, imo. I much prefer
Dot above the other nns.
Dolly seems especially childish,
Dodie makes me think of dodo birds, and
Dottie reminds me of a very absentminded person, not least because I know a woman named
Dottie who is very ditzy.
Dot is cute though.