It's rare that a sequel improves upon the original formula of a movie. Too often, film franchises are stretched out into a one-note story, with characters and plotlines suffering from being rolled thin and crispy so that studios can line their pockets with a popular name. In fact, so often are they unnecessary and unpleasant that they're defined by the horrible sounding disease sequelitis - an industry plague that that has franchises uncontrollably leaking out all sorts of crap just because... they can, really.
However, when sequels get it right, they're some of the best films out there. Bringing old stories back to life and imbuing them with a new direction can be one of the most rewarding aspects of cinema, and revitalising characters that we can then see grow and develop is a uniquely great thing to witness.
Returning characters for sequels allows more time to deepen and expand upon their established stories to excellent effect - as some of the best arcs come when the films already have a persona's foundation to build on top of. Whether its fixing old problems or doubling down on the awesome, these are some of the best characters that really do prove the classic saying: the second time's the charm...
10. T-800 - Terminator 2
Arnold Schwarzenegger as the titular Terminator was an instant classic back in 1984, but there's no doubt about it that T2 is the lasting memory of what the franchise has to offer.
Where the original, unstoppable killing machine from the future was an entertaining watch, by the second movie Arnie had imbued his electronic robo-skeleton with some real depth - transformed into an almost-human hero and father figure that had far more to offer than just his capacity to kill things really well. Though that was definitely still a highlight.
The T-800 of Terminator 2 made Schwarzenegger's role far more complex, getting to unleash the same menacing villain from the first movie but giving him humour and a strange sense of empathy as he protects the protagonists.
This plays fantastically well against Sarah Connor's development into a pure badass too, with the growth from The Terminator's gritty, dark narrative into T2's flamboyant sci-fi action one of the best steps of James Cameron's filmography. It's just a wonderful extention of a great idea all round.