These questions are too hard to nail down to just one so I'll list a few of my all time favorites;

Once upon a time in America is one of my favorites in my opinion the greatest mob film of all time, both De Niro's and James Wood's performance where mind-blowing if you do watch it for the love of fucking god watch the full version, it's a 4 hour flick you CAN'T do it justice if you cut 2 hours out that was ridiculous!

In Bruges is a much more recent film and although I've never been a big fan of Colin Farrell his performance in this was brilliant, it's a black-comedy and one of the best near enough every line in the film is pure genius... a must-see before time runs out.

In The Loop is another black-comedy, a kind of synical british humor style take on the build up to the invasion of Iraq it's a spin-off of the tv series "The thick of it" but it's fantastic as a stand a lone film, it features some of the greatest characters of all time and most hilarious lines of all time...

Jay & Silent Bob: Strike Back a much less witty and high brow film, this is a fantastic stoner comedy and includes one of Will Ferrel's best characters imo as well as ofc Jay & Silent Bob again amazing characters... (Also good in films like; Dogma, Clerks & Clerks 2)

Star Wars films; Episode 1-6 there isn't much I need to say I'm a massive fan of SW not just in the films so I instantly love it more than most for the lore element and seeing things in film often shows a lovely perspective as it does in these films... (Lore is the only thing that makes that Clone Wars cartoon series bareable, not that I watch it.

Any adaptation of J.R.R Tolkien's writings of course Peter Jackson's adaptations are the best known the LOTR trilogy was a fantastic hit and with the recent release of the first installment of his The Hobbit series it's reached new levels in fame. However the original Hobbit adaptation on video tape was just as fantastic as I think they're all respectful of J.R.R tolkien's wishes, e.g Rivendell in Peter Jackson's films showed an uncanny resemblence to Tolkien's drawings in the 70's - mucho respecto for that :p

There's so many more that I haven't mentioned but frankly it'll take too long, hope you find something good out of that list! :'

Oooops I forgot TV shows so I'll rush this and not describe them, much:

Peep Show one of the best comedy series of all time I've been a fan for a long time so it's amazing seeing how they've finally made some new episodes recently.

Game of Thrones a fantastic series very raw and a lovely homage to the book I can only hope they do a series for every book.

The Walking Dead I'm something of a zombie fanatic and was expecting it to suck when I watched episode 1 years ago but I've loved it since then I've never read the comics but I love how they have characters that aren't in it... (Daryl and Meryl, if that's how you spell them, aren't in the comics - adds to the cliffhangers of every episode)

There's a few again more I cannot be bothered to write about but yeah, check em' out...