The bed in "my" bedroom (in quotes because, well, all the bedrooms in my house are mine!) is a single bed with no headboard and lots of pillows and animals on it.
I also have a queen bed in my guestroom. It also has no headboard and also has a decent number of pillows and animals on it.
I guess when it comes to a fantasy bed, like if I were super rich and would be expected to be a little indulgent with my bedroom, I might enjoy having one of those cool round beds, and I've always liked the aesthetics of those bed curtains on canopy beds and stuff. I do also kinda think it would be classier if I had a headboard, but I've never really cared about that.
I had a waterbed when I was in high school and I definitely wouldn't do that again. If you spend a lot of time in bed reading or doing leisure activities, waterbeds aren't very comfortable.
The novelty beds are also kinda fun. I love the ones in fun shapes. Maybe I would like to have a bed that looks like a donut.