both are correct.
but first one seems more polite and honorific.
so when you meet an older person, you can use it.
반가워요, it sounds friendly.
when you meet a younger or a same age person, use this one.
you can also use first one in this case, but if you want to look a socialized person, 반가워요 is better.
Please don't use it in front of order people. maybe they think you're rude or an overactive person.