It's great to hear about so many marriages made in Disney -
- but to get back to the OP:
AreWeThereYet said:
Help. DW and I have been married for nearly 18 years, but I am slowly coming to realize that we may not be the best fit for each other. I think we may be unequally yoked - I don't believe we share the same love and devotion for all things Disney.
... please share your sad story of inequality. Perhaps with enough fellow "unequally yoked" friends to commiserate with it will help ease the pain.
"Hello. My name is Pogo791, and I'm feeling the pain of being unequally yoked."
Yes, I've got to come out of the closet on this one.

My DW of 25+ (very happy!) years definitely does not share my love of Disney. She's gone along with me on visits to all four Disney parks, but resists going back again with a paraphrase of the "been there, done that" argument - and no amount of references to new attractions will get her to budge.
Now it seems that the only way I can get her to a Disney park is to wait for a new one to be built. She's agreed to come along to Hong Kong and even spend a day at Hong Kong
Disneyland, as long as she can spend the rest of the time sightseeing elsewhere, and shopping. (HK Disneyland opens Sep 12; we're going soon thereafter.) As things stand, that means that after that trip, it'll be a long haul before the next time I can get her to a Disney park - probably in Shanghai!
Since we don't have kids, that means that every time I go to WDW, it's solo.
But there are upsides. We do a lot of travelling together, and enjoy every minute; several vacations each year. She's very happy to have me scoot off every now and then for a week at WDW; I try to make it easier for her by arranging (and paying) for her trip during the same period to someplace she likes. And going to WDW solo has its advantages - I love getting up early for a jog and a morning coffee (fill my BWV mig to the brim, thank you kindly, hanname) and deciding then and there which park to get to, before the rope drop.
Although I'd love to share WDW and the other Disney parks with my significant other, I simply have to respect her likes and dislikes. I bought into the whole package, and I'm glad I did!
Bottom line, AreWeThereYet? As long as you're happy together (you have been married 18 years, so there must be something!), that's the main thing. And even if you can't share WDW with her, there are millions of people out there (many of them on this Board) who share your love for Disney ...