The angel Gabriel is mentioned by name four times in the Bible: twice in Daniel, where he explains Daniel's visions of the end times; and twice in Luke, where he tells Zechariah and Mary of their children.
The connection between Daniel's vision of "a most holy [one who] will be anointed... [and] shall be cut down" and the birth of the Messiah is clear enough. Gabriel's role in salvation history is one of announcing Christ's arrival -- and the traditional belief that he will be the angel who blows the horn announcing the return of Christ in glory is well known.
Less well known is the traditional belief (recorded in Jewish midrash) that Gabriel was the angel who led Adam and Eve out of the Garden after their fall. Thus he who gave the bad news to the first Eve is he who gives the good news to the second.
(The Catholic Encyclopedia notes that, while Christians see Gabriel as "the angel of mercy" and Michael as "the angel of judgment," Jewish traditions reverse their roles and "attribute to Gabriel the destruction of Sodom and of the host of Sennacherib.")
A curious note to make of what you will: In Daniel 8, Daniel learns Gabriel's name, and after the angel leaves, writes, "I, Daniel, was weak and ill for some days...." In Luke 1, Gabriel only announces his name to Zechariah after the priest doubts his words, and Zechariah becomes dumb. Mary is not told (in the Gospel account) the name of the angel who appears with the greeting, "Hail, full of grace, the Lord is with thee: blessed art thou among women," and she is, to say the least, not left physically disabled following their meeting.
Maybe that's coincidence (after all, St. Raphael announces his name to Tobit's family, and nothing untoward happens to them ("No need to fear; you are safe.")), or maybe the way to look at it is that no visit of Gabriel leaves you physically unaffected. Still, if I ever meet an angel who doesn't tell me his name, I think I won't ask.