My very favorite would have to be Friesans. I think they are absolutely STUNNING. I love black animals anyway...Unfortunately, they are VERY expensive, $20,000 and up and not very common. (Martha Stewart has a few. I read in a magazine that she doesn't let them out during the day as it will fade their coats so she only lets them out early morning and early evening.)
I also love Saddlebreds. I love their long long legs and l o n g necks...I grew up riding them though so I'm prejudiced.

Quarter horses are great too. They are like the golden retreivers of the horse world! Most of them are very even-tempered and pleasant to be around. And they are very well-rounded. You see them in almost every different type of riding arena, hunt seat, western...I belong to AQHA and have seen them doing dressage too. Unfortunately for me, I am fairly tall and most quarter horses are around 15 hands although I have seen some larger ones. I was looking to buy one this summer named Cooley that was 15.3. Unfortunately the deal fell through but he was a doll! And perfectly square from the front and rectangle from the side!! He won every halter confirmation class he was ever in. I wil have to post a pic sometime as I still keep in contact with his owner. Anyway, I would look ridiculous on a small horse, with my legs hanging to the ground! LOL!!