(it's) good to see you (again)
I'm happy that I encountered you (again); I like seeing you. It's so good to see you, Paul. It's been too long! Good to see you again, Lily—how've you been?
(It's) good to see you (again).
a polite phrase said when greeting someone whom one has met before. Bill: Hi, Bob. Remember me? I met you last week at the Wilsons'. Bob: Oh, hello, Bill. Good to see you again. Fred: Hi. Good to see you again! Bob: Nice to see you, Fred.