Hi David, and welcome.
I think the answers to your question are going to be many and varied, as we all have our own personal tastes and favourite veg. For me, if I can only choose five, the ones I couldn't be without are as follows:-
Home grown strawberries - nothing to beat the taste.
Ditto - home grown raspberries.
Fresh runner beans, straight from the plot.
The first new potatoes.
Fresh peas, mostly eaten raw before they even leave the plot.