Raven
Radiant is very nice. It begins with the letter r.
By nice, do you mean long? Very long list, if you want official list, go to a dictionary. A long word that start with an r would be, Reindeer.
Nice
Yes is a nice word. Yummy is a nice word.
nice day r out to play
Radiant is a nice compliment. Reliable is a nice compliment.
Outstanding is a nice complimentary word. Optimistic is a nice positive word.
Outstanding is a nice complimentary word. Optimistic is a nice positive word.
Righteous
Yes is a nice word. Yummy is a nice word that starts with the letter y.
interesting is one word
Vivacious is a nice word. Virtuous and vigilant are additional nice words.