Basically the entire cast is really good, and also includes Toni Collette, Greta Scacchi, and James Cosmo. Oh, and Ewan McGregor makes an appearance as the tricksy Frank Churchill, though he's almost unrecognizable under that shock of hair.
To be fair, the fellow does have one or two other things on his mind, as he's involved in a secret romance while being flirtatious with Emma to throw people off the scent. But he's certainly not opposed to making a spectacle of himself.
There's also a 2020 version of Emma which I haven't bothered to watch... the trailer makes it look like the characters are behaving in an annoyingly modern way and I'm not up for that. Maybe the trailer is deceiving, but with so many decent adaptations of Emma to choose from, why take the chance. Anyway, it's always better to pick up the book and have a go at that instead.