4. Brian & Stewie
You'd think Family Guy would suffer without its overuse of cutaway humour, but in Brian & Stewie we have one episode that does away with this and instead focuses on strong characterisation - it's experimental, but wholly successful. The simple premise is that Brian and Stewie are locked in a bank vault overnight and forced to coexist in a tight space. Crucially, in one of the episode's throw-away revelations, we are given more insight into Brian's troubled mind again as we find that he keeps a gun in his safety deposit box in case he ever decides to kill himself. This exploration of depression and low self-esteem may be intercut with gross-out humour such as Brian eating the contents of Stewie's diaper, but at its heart it is a very moving story between the two strongest characters. It showed Family Guy's willingness to try new things (despite frequent accusations of creative laziness) and the show-makers' ability to cover dark subject matter head on. These are things we don't see from the show very often, which makes this episode stand out. Once again we are reminded how important Brian is to Stewie and more importantly, the overall Family Guy experience which makes his untimely demise all the more crushing for fans.