Clerks is definitely my favourite, I was introduced to it during uni by some fellow nerdy mates at a small cinema group. Back then I had a long hair, a long coat and a beard and my mates called me Bob.

That was kind of ironic since I knew next to nothing about Kevin Smith going into the film. The humour was a breath of fresh air at the time - sometimes witty, sometimes puerile but always entertaining with references galore.
One of my buddies even had plans to make his own 'homage' to Clerks a few years ago...but yeah, those were the days. [img]smile.gif[/img]
Berserker!

(power chord fill)
Worst? Well, I haven't seen Jersey Girl, but I tend to agree that Jay and Silent Bob Strike back wasn't quite up to scratch - it contains far less intellectualising in geekery, too many jokes about bodily functions and more slapstickery, so I was a bit disappointed.
Second favourite would probably be Chasing Amy. Made me rethink many common assumptions at the time. [img]smile.gif[/img]