Butternut Squash is generally shaped like a large pear and has a thick, cream color shell with a deep orange color flesh. It has a slightly sweet taste and is excellent for cooking, in recipes, and makes great soups. One of the best and most healthy ways to cook this squash is to cut it into chunks and steam for about 7 minutes. It is also great baked, but it is best not to boil it, since it loses much of its nutrients to the water.
Acorn Squash has a deep green shell with orange speckles and a more pale yellow flesh. Its flavor is somewhat sweet, but has a more nutty and peppery flavor. I find this squash great for baking.
Spaghetti Squash is a large squash with a thin, hard shell. The flesh is light colored and can be pulled with a fork to resemble spaghetti. This is such a great vegetable to use as a base for pasta dishes, instead of pasta!
Kobacha Squash has become popular in recent years. It is actually a Japanese winter squash. The taste is more similar to sweet potatoes, creamier, richer, and sweeter than most other winter squash. The shell is less thick and is actually edible, it gets soft when cooked.