1) Watching this film will change forever your perception of the bank heist genre, making you question the contrived cinematic conventions these films usually make use of.
2) The source of this film's paradoxical and/or farcical elements spring from life itself, not from film or pre-existing cinematic conventions. Sometimes, the absurdities of life are so great, they dwarf those included in any form of fiction. Without even trying to make that point, this film captures that concept beautifully.
3) Its tone in relation to the homosexual theme is ahead of its time. In fact it's ahead of OUR time, even, in hardly making an issue out of it at all - it just IS.
4) It captures the climate of the 70s in a manner so sober, you'll remember its unshowy yet authentic feel forever.
5) Lumet's film brings to life the concept of the distorting lens of the media and how different groups with different agendas will turn an outlaw into a hero, with far more efficiency than Oliver Stone's brash, bloated, childish and repetitive Natural Born Killers.
6) Watching this film will illustrate to the younger generations exactly why Al Pacino has earned himself the legendary status he probably no longer would deserve with his performances of the last 10 years alone. **SPOILERS**: Just watch those last ten minutes of him handcuffed against the bonnet of a car, where he doesn't say a word, but speaks volumes with his eyes and his soul just oozing out of every frame at the end of the movie; you'll remember those eyes for as long as you live!
7) Watching this film, you'll realise that firing a gun-shot is a BIG DEAL in real life, and that other films make too much use of gun fire in a highly contrived way.
8) All that tension deriving from pointed guns unable to fire a shot OR move away you realise Tarantino must've taken notes sometime along the way.
9) No genre is old or done too many times before if it's handled with this amount of freshness, inspiration and talent.
10) Watching Dog Day Afternoon for the third time has filled me with the same amount of wonder at the power of truly inspired but unobtrusive film-making as it did first time round.