I've always found getting someone a fragrance to be a challenge. How you smell is such a personal thing. So buying someone a fragrance you don't know they already like is a big risk. So what I suggest is to get a collection of decants and/or mini's to let your SO give them a try and then buy the preferred one. This way you have a better chance of getting a hit. Based upon your post I get the sense that you are looking to expand your SO's fragrance horizons so this could be very good.
Anyway a suggestions of one to look at is Vera Wang for Men. There are a lot of people who complain about this fragrance's longevity but I've not had any problems.