Not only do critics and viewers seem to love this movie, but other filmmakers seem to love it as well and incorporate elements of the Third Man into their own films. Some of these newer films are less than all-time greats (The James Bond film The Living Daylights borrows elements such as the old friendships, the fake death, the ferris wheel, a performing girlfriend with forged papers and even the "Ein Balloon mein Herr?"--although in normal fashion Bond gets the girl instead of having her walk away)--but some other films that nod in The Third Man's direction are much better such as the Coen Brothers' Miller's Crossing (the characters have been shifted around and the setting is very different, but the same themes echo throughout--I only wish the final scene was as amazing as in The Third Man.) I'm sure there are many other films that have been influenced but I can't think of any at the moment.
Review of The Third Man
