I think it's becoming more and more the norm for couples to pick out rings together. I'm not anywhere near getting engaged, but my sister recently got married, and her and my brother in law picked it out together. She got a 3 stone ring with a princess diamond for the center, and two smaller princess cut diamonds on the sides in white gold.
For myself, I've already decided I want a vintage ring. My favorite diamond ring I've ever seen is my grandma's ring from her first husband, and it has the most unique setting I've ever seen. Her then-fiance designed it, and I could only describe it as a "portrait" setting, as in, there are no prongs, it is set like you would frame a picture. I don't think it would be considered pave, either. It also has some beading and filigree work. It's dainty and delicate and exactly what I want for myself. I don't really care about the size of the diamond, it's all about the setting for me. I dislike all pronged settings, I don't know why, but just something about them irks me. I've already told my mother that if I don't go shopping with my future fiance, she is going in my place, because we have very similar tastes in jewelry.
/novel