So i'm about to finally propose to my girlfriend of almost 4 years and i just wanted some advice from the ladies(or guys) as to what women really look for in an engagement ring.
I am limiting my spending to 15k, unless there is something out there that i deem worthy of spending more. 
She likes white gold and wants a "real" diamond.
I was going to just take her to a nice place and let her pick out what she wants but i want it to be a surprise. She knows it's coming, but i want to really shock her with the delivery.
Throw me some ideas people and pics would be nice.
I really know nothing about these things, i'm more of a nerdy Science guy, not a fashion guy.
Besides getting a legit diamond, what else should i really look out for?
Our Buddhist ceremony will be at the end of November and i will need the ring before that.
So ladies, what do you like? what would you change about your own ring?

Congratulations Overload!!!
Let me say that what we ladies at getbig like doesn't mean a darned thing! It's what your fiancé likes that matters.
What are
her tastes when it comes to rings? Base your decision on that.
When it comes to diamonds, keep in mind the 4 C's: Cut, Carat, Colour, Clarity.These will all factor into the price of any diamond you purchase.
Is she a very traditional sort? If so, perhaps a brilliant cut might be appropriate.
Does she like fancy cuts ie: pear shaped, marquise, emerald cut?
Is she all about the bling? Is she a woman for whom size matters? If so, you might want to place importance on the size of the diamond over clarity.
Is she a woman who prefers quality to quantity? Then place greater emphasis on the clarity of the stone over the carat weight.
Would she prefer a fancy coloured diamond? ie: a canary diamond?
Remember: When choosing the engagement ring... it's all about
HERI know you want to make it a surprise, ...you can still do that, ...but make sure it's a ring she's going to like.
Hopefully she'll be wearing it for many years to come.
Hope That Helps