I vote for the jewels. I would save the spa treatment and give that for Christmas, Mother's Day or a birthday. An anniversary gift is so much more meaningful to me because it's about our wonderful marriage and what we've built together. When I look at the jewelry my DH has given me over the years on our various anniversaries, my heart just melts as I remember which anniversary it represents and where he gave it to me. Remember it's supposed to commemorate the relationship between the two of you, not just her (like a birthday would do). Unless you were planning on a "couples" spa treatment. Also, if you do go with the sparklies, be sure to take her to a romantic restaurant when you give it to her.