I find lettuce, olives and fresh tomatoes bitter but I can eat ketchup, tinned tomato soup, margarita pizza etc., probably because there's added salt.
You might be interested in this article:
http://en.wikipedia.org/wiki/Supertaster
I'm convinced I'm a 'supertaster'. For example, mushrooms taste like garden soil to me (I don't eat garden soil! I've accidentally put my finger in my mouth after doing the weeding). I find it fascinating that people can just pick up a mushroom and pop it in their mouth.
I find fresh coffee very bitter (I can only drink the dreadful freeze dried stuff with half a cup of sugar).
Most disappointingly, I really don't like the taste of alcohol. If I try to drink a spirit, even if it's only a tiny sip, it makes me want to gag! Most spirits just taste like hairspray (again, I don't drink hairspray...). I can't relate to the enjoyment of beer at all - I I think few people can relate to my aversion to it. I was very please when alcopops were invented!