Ray Park gets more to do that's substantive, and gives him characterisation, than Christopher Lee gets across two entire films in my honest opinion.
To see the better versions of them you have to commit to The Clone Wars Series, and The Clone Wars pilot masquerading as a film before that even, but before either of them existed we got Samurai Jack creator Genndy Tartakovsky's The Clone Wars using traditional animation that introduces many of the elements you will see in the 3D iteration.
And that features the debut and best version of Grievous.
I recommend watching the whole thing, the two volumes only amount to around a film's length, and it's really good fun stuff.
But if you're interest in just the General: https://youtu.be/oxAaSrbGnyo