Great thread idea!
Eastenders : Stacey Slater, Max Branning, Tanya Branning, Tiffany Mitchell, Michael Moon (there are others but don't want to ramble on)
Corrie : Steve McDonald, Graeme Proctor, Candice Stowe, Kylie Platt, Jack and Vera Duckworth (plus more)
Emmerdale : don't watch it anymore but Kim Tate is a standout character
Hollyoaks : far too many to mention over the years, my favourite soap of all
Currently really liking - Mercedes, Lindsey, Darren, John Paul, Cindy, Freddie and Dodger.