There are a number of different varieties of this beautiful fruit: Black Beauties, Ping Tung Asians, Fairytales, Graffitis and even White Eggplants.
Some folks might not like the bitterness of eggplants, but you can solve that by salting them and letting them sit. The moisture (and the bitterness) will be pulled out. Then rinse them off, pat them dry and you're good to go.
I also advises you to cook eggplant until it's soft. When you touch it, it should be a bit mushy. It shouldn't be firm at all. If it is firm, it's undercooked and that's where your bitterness will come.