If you aren’t so sure that you and your wife ever did date, then maybe you can’t actually claim that your wife is the most attractive woman you’ve dated. 
[Of course, I don’t really have any idea what the ambiguity is that lurks behind that “it’s not really so clear”]
Yes I imagine if there was someone else they found more attractive they’d be better off doing everyone a favor and not getting married.
I’m just gonna have to jump in here and say:
A man doesn’t judge a book by it’s cover.
If attractiveness were a fixed objective quantity, it would seem plausible that many men would end up marrying women who were not their most attractive girlfriends, if only because there would seem no particular reason to assume most men would only date women of strictly increasing attractiveness through time, and, thus, we would be led to believe that many men would end up in such position as that, after reaching and losing a woman of a particular peak attractiveness, they never, for whatever reason, date someone so attractive again.
However, it also seems reasonable to say that, in reality, attractiveness is in many ways a varying subjective quantity, such that, mushy as it is to say it, for many men, the woman they end up marrying becomes, to them, the most attractive one they’ve ever met.
Ever get to the mall 3 days after the sale started?
Physical attractiveness is often a significant factor in whom we are most likely to pursue and date. Past a certain point in developing the relationship, however, it is overshadowed by deeper qualities. I would say that precious few men (generally fools, at that) would only consider marriage with the most physically attractive woman they’ve dated, to the exclusion of the others.
Of course, the question is complicated by different standards of attractiveness (some like curvy women, some like slim women, etc.) and different types of attraction - physical, emotional, intellectual, etc.
I did not marry my most attractive girlfriend.
I did not marry my girlfriend who was best at sex.
I’d rather my wife be kept ignorant of these opinions.
The girl who holds those two titles would not have been a good wife.
Yes, yes, but can I have her number?
Sorry. She’s only into chess teachers with British accents. Where you gonna find one of those?
Fifty bucks a month and my lips are sealed. 
Checkmate, guvn’r!
Now make with the phone numbers.
I did marry my most attractive girlfriend. She was also the most intelligent and the messiest.
Oddly enough she was not the shortest and yet she is only 5’2". She did have the longest hair. I love long hair. It was the first thing I noticed about her.
I guess she was the richest, but she owed more money than she had when I started dating her. Her parents were better of than my other girlfriends though.
How to actually answer the Op’s question? No doubt there has been a few polls on this questions over the years. Perhaps a search of a periodical index?
Jim
If you are limiting it strictly to physical attractiveness, no. I dated several women who were (at the time) more physically attractive than the Lovely and Talented Mrs. Shodan.
In terms of the overall package - looks, personality, compatibility, common interests and background - nope, she’s it.
FWIW. Our twenty-sixth anniversary is in two weeks.
Regards,
Shodan
My most attractive girlfriend was an incredible flake and had various other emotional problems. There are many times I thank goodness she WASN’T the one I married.
Ed
Ditto x4. 
In my case, said ex- girlfriend had been divorced twice before we met, married again several years after we broke up, and divorced again.
You’re getting into “junk in the trunk” territory now. Almost a different matter in my opinion.
I echo these sentiments exactly. (I’m not married yet, but will be this summer.)
I’ve only had two long-term relationships (by which I mean longer than a year). The first of these, she was hot. Really hot. Men would literally stop her on the street and make a move on her as we were walking along like I wasn’t even there. She was waaaay out of my league, but I happened to be in the right place at the right time and we were together for two years before she came to her senses and moved on.
But although she was smoking hot and wonderful in bed, I could never have married her. For a start, she was a little crazy and immature (although a year older than me), and for another thing my insecurity over her being out of my league would have been too much to handle. I’d have been convinced she would look elsewhere, and I reckon I’d have been right.
I’m deeply in love with my fiancee, who is very attractive in a more manageable girl-next-door kind of way. We also have a lot more in common than my ex and I ever did.
I thought the stereotype was that closeted gay men marry fat unattractive chicks because it’s easy to woo them and takes little effort on their part to maintain the semblance of a relationship. I know I’ve seen it parodied on a couple of shows or movies (Mr. Show, maybe?) I know a kid who is gay as a tangerine but his dad is a minister, so I don’t know if he realizes/admits it. He is married to a girl who weighs about twice as much as him, and who fawns all over him, while he is pretty indifferent to her.
What a phrase!
Are 20 somethings (the cohort in which men and women usually casually date) more or less attractive, as a rule, then the 30 somethings, considering that’s the age age to settle down and marry?