I might be one that says I prefer to ride alone. However, this is based on my previous experiences. I grew up going to
Disneyland several times a week and it is practice there that they don't sit parties with strangers unless it is more than a 2-seater (Indiana Jones, Splash Mountain, Radiator Springs Racers, etc.). So, to me, I wasn't used to it. When I started to go to Walt Disney World a lot last year, I was very uncomfortable getting on rides like Big Thunder, Seven Dwarfs Mine Train, and other rides that don't have a single rider line with a stranger. In fact, the first time it happened, I got on the ride as if I was going to ride it alone until a CM told me to move over for another single to get on the ride with me. I was very shocked that this was the procedure at Walt Disney World.
Now, I am absolutely ok with riding on rides that HAVE a single rider line. Sometimes I go in the regular queue like Expedition Everest, because I like to sit in certain locations. I always know I will be placed with a single rider. I have also used the single rider lines on many occasions at WDW and DLR.
So, to make my answer a lot clearer...I prefer to ride alone on any attraction that doesn't have a single rider line. Once I knew the process at WDW, I would begin asking to ride alone, and the CM would always let me ride alone. When I am placed with a single rider on rides, sometimes I spark a conversation. Sometimes I don't. I also need to say that I am 6'4" with my height in my legs. I don't want my legs touching a stranger where I know the ride restraints will be tight like on 7DMT. Plus, I tend to slide on BTMR, and I don't want to ram into the person next to me on the tight turns or have the stranger ram into me. I enjoy rides a lot more when I'm alone or with friends/family.