Some 50th anniversary quotes include: "They call 50 years the Golden Anniversary; the two of you shine and are great examples of what a marriage should be," and "Our wedding was many years ago. The celebration continues to this day." The 50th anniversary is the golden one, and quotes chosen should reflect this.
Some more 50th anniversary quotes are: "To me, fair friend, you never can be old, For as you were when first your eye I eyed, Such seems your beauty still." This is attributed to William Shakespeare.
An abridged quote from Karl Fuchs is: "A partnership like yours is rare; 50 years you've been together!"