I'm interested to know the best spices for bread.

I've been making heavy bread with whole-wheat, oats and nuts. Some recipes
call for 5 spice and cinnamon with fruit. Anything else good to throw in
there?

I've been making bread with onion/tomato/cheese, which has come out quite
nice, but I'd like to give it a little more flavour, what spices do you
suggest.


Thanks