I agree with your choices, Abi and Lea.
The Brannings and Beales are both brilliant and strong families. I like Jane and Tanya in their motherly roles, with them both being rather realistic characters. Max is a slimeball, but still an interesting character (one I love to hate) and Ian Beale is a character I've always loved. The child actors in both families are very strong actors too. Both families just come across as being realistic.
As for the Mitchells...well they irritate me greatly. I find it hilarious how Phil "don't mess with me" Mitchell still tries to come across as tough and strong after all these years, and Peggy constantly spouting on about "famillleee" is very very annoying. Ronnie and Roxy are good characters in my opinion but as soon as they've arrived, they've come under the Mitchell curse of saying the words "we're famillee, no one will mess with us". Overall, the Mitchells are so predictable and when they are in a crisis, you could probably predict the dialogue for them. Phil: "No one will mess with us Mitchells"... Peggy: "We're familleee and we stick together coz we're Mitchells".