First Impressions

For anyone who is happily married or in a successful, long-term relationship, what were your first impressions of your significant others? How did you know/ when did you realize they were the one? I'm single, 26 years old, interested in dating but only for the purpose of finding Mr. Right. I know looks aren't everything, and I'm willing to give any nice, respectable man a chance. But should I give it more than a few dates? I've seen this one guy at my church a few times, and we have some common interests and even practice the same religion , but I don't think I like him more than as a friend, even though I know he's crazy about me. Do I pursue this relationship further to see how it pans out, or should I let it go and tell him 'No thanks'?