Depends on your fiancé really. I always personally like solitaire rings. Has she given you any clues?
CommentAuthorMetalliCat
As it's something that your fiancee is going to be wearing for the rest of her life, you really need to think about what she likes - styles, metals, stones etc. Look at some of her other rings - are they big and showy, or small and elegant, etc? Ask her questions about the rings she already has (if she bought them) - what does she like about them, which are her favourites etc. My engagement ring is bespoke and completely original. My fiance bought a lovely ring to propose with, but he knows I'm rather particular, especially as I don't wear much jewellery, so it was returned and we went hunting for something I liked afterwards. What I found is that most of the rings in shops or online is very same-y and not my style. Instead, I started looking at jewellers who create bespoke pieces. I now have something I absolutely love, which was worth the wait and is perfect for me. It does mean a longer process, it can cost more and you may have to get the wedding rings made by the same jeweller due to the bespoke design of the engagement ring, but it's worth it.