My "love at first sight" was the benchmade 51, I was saving every dollar I could scrap up to get one, that was about 5 years ago.
The only knife I had remorse after buying was a DLC manix 2, I was about to return it because I didn't like it at first. Then I took it to work for a week and realized how wonderful it is! The ergos, the grind, the lockup, the ball bearing system, everything just spoke to me after using it for a week. It's now one of my favorite design!