I don't really have a specific knife like that, I try not to buy if I'm not quite sure if I will like it.
But as a design in general, I started to really like slipjoints and in the last couple of years they are at least half of my purchases. I thought they are boring, outdated and unsafe. Once when I was in a store, I handled Benchmade Proper that was on display. I wasn't interested in it, just to check micarta and because there was a long queue. Liked it so much I bought it and started to like slipjoints.
Another general thing is smaller blade size. When I started, I wanted only 3,5-4 inch blades. Everything smaller I thought is too small for a main blade and I don't want to carry a secondary. By accident I bought a small knife, the design and price were good enough that I didn't check the specs and it looked bigger on pictures. I used it for a few days and decided shorter blade length is good enough and smaller size and wieght makes it better to carry. Now I usually stay within 2.75-3.25 inches blade range that I earlier avoided.
Probably the closest specific model I didn't like but eventually started is Spyderco Stretch 2. I got it in a trade, it was a good deal and I thought I will trade or sell it later for something else. I didn't dislike this model, just Spyderco in general because how ugly opening hole makes the blade look. I did some tests and it was such a great slicer I kept it and don't mind how it looks. I even like the blade shape much more than their standard PM2.