No offense, but I think it's horrible when women pick out engagement rings, or dream them up and almost expect them. For one, in my opinion, you'll look silly when you either don't get what you want or don't even get engaged. And for two it puts a ridiculous amount of pressure on the guy who simply wants to spend his life with you. It's hard enough even making the commitment without people in your ear going "Tiffany's! Kay! Ben Bridge!" My friend basically planned her own engagement. They went to a big engagement ring store here in my town, she tried on a bunch of rings, watched him order and pay for her ring (she kept guiding him on what to have inscribed inside of it) and then threw a party ("Just a few friends over for cocktails!) Where he "surprise!" knelt down and proposed to her. TACKY. I didn't even go because I knew wtf she was up to.
...But I've digressed haven't I? Basically as long as he put thought into picking a ring out that he thinks is a representation of how he feels for me, and not a representation of feeling pressured by me, family or friends, I'll be happy. So far he knows what I like and what looks good on me, so if our relationship ever does get to that step, I'm sure whatever he picks out for me will be perfect.