It means to make someone really happy. It's used very commonly with the word day (I made his day).

Of all the events or things that happened, this event, meeting with the "I" of the sentence was that event that was the defining one for the night. The implication is that it was positive. . He was having an ok time, but wining the bar raffle really made his night. The music was fun and all, but you being with me made my night.

It means that you made him really happy.