Whats your favourite sandwich filling ?

I just made a lettuce,sliced tomatoe,cucumber,grated raw carrot,red onion,with a thin slice of cheese,and a slice of cooked chicken,coleslaw ,light mayo and tartare sauce on Wholemeal bread. mmmm it was delicious..tell me your favourite sandwich and all its ingredients so we can all swap recipes and make them up next time we want a tasty treat.