Wikipedia has a great list of signature phrases — the unique lines associated with real or fictional characters, and they cover a lot of territory. Read it over; it will bring back some memories.
# “Aciao good night!” (Aciao bonsoir!) – P.P.D. the puppet in the French satiric show Les Guignols de l’Info, at the end of most of his broadcasts
# “Actual retail price, $ (dollar amount)…” – Bob Barker, on The Price is Right (He follows it with “…a difference of $ (dollar amount)” in the Card Game and concluding Showcase round, unless a contestant has overbid, in which case he says, “You’re over.”)
# “Aflac!” – Aflac Duck
# “After these messages, we’ll be right back.” – sung at the beginning of every commercial break on the old ABC Saturday morning cartoons
# “Ah-one, and ah-two…” – Lawrence Welk, directing his musical performers on The Lawrence Welk Show
# “Ahh, shaddap!” – Foghorn Leghorn on his cartoons. Also said by Sylvester and Yosemite Sam.
# “Ain’t I a stinker?” – Bugs Bunny
# “Ain’t the beer cold!” – the late Baltimore Orioles broadcaster