I just had a formset where each form had a pre-loaded ModelChoiceField, and I needed to display the name of the selected choice in the template.  On a model you would just use the get_FOO_display() method, but a form has no such convenience.  I found a number of almost solutions on Stack Overflow, and after poring over them I concluded the best solution for my problem was to add the following method to the form:

class QuestionLanguageForm(forms.Form):
    ''' basic QuestionLanguage form '''
    language = forms.ModelChoiceField(queryset=Language.objects.all())
    short = forms.CharField()
    place_holder = forms.CharField()
    long = forms.CharField(widget=forms.Textarea(attrs={'rows':None, 'cols':None}))

def get_language_name(self):
    ''' returns the name of the selected language '''
    try:
       return Language.objects.get(id=self.initial['language']).name
    except:
       return None

This way I can use

{{ form.get_language_name }}

in my template and it prints the human readable name of the language set in my initial data.  This code is not robust; I catch all exceptions and ignore them because I’m only using it in a circumstance where this code won’t raise an exception (and in case it does, at least it won’t fail catastrophically).  However proper error handling could be added pretty simply.  #ExerciseForTheReader

P.S.  The title says “selected” value but I’m actually using a pre-loaded value, not anything user selected.  If you need to get a user selected value you could use self.data or self.cleaned_data instead of self.initial.