Straight for me. I have only a couple of bent ones, and one to come, but my best smokers by far are straight pipes. My ideal pipe is a straight billiard under 30g of weight; That's what I usually look for, although I get carried away by the beauty of some bents.
I have a pipe rest in every table. I don't like to hold the pipe in the mouth too much; i prefer to leave it in the pipe rest, do whatever and take it back, or keep it in the hand, if I can. Even the bent ones bother me if they hang in the mouth too long.
Despite that, I am more known around these parts by those bent pipes, which I smoke to/from work riding a motorbike...
I have owned a number of straight and bent pipes. However, these days I prefer straight. Honestly, I just like how they look. I don't think any pipe looks better and more handsome while I smoke it than a straight rusticated pipe.
I started out preferring the look of a full bent but as I got more and more in to pipe smoking I found out that I really like them both. It's all about the execution to me and if it all comes together in my eyes then I'm in to it.
I'm a straight man (in every sense!).
I just feel that bent pipes age me more than straight ones do, and I'm 56. Being a typical bearded pipe smoker a straight pipe looks more direct, focussed and businesslike. A bent pipe makes me look like a bear.