Which do you prefer and why?
I've got a mix of both. Bents hang better, but straights smoke dryer. With bents everything drains down to one spot and you can get gurgling. With straights you can just flick them to clear them of any liquid - no pipe cleaner needed. If you smoke meerschaums then the moisture isn't an issue at all, so I prefer bent meers for the balance.
Churchwardens are great pipes - I got my first one about three weeks ago - A Stanwell HCA.You know, I've never smoked a churchwarden, but I've always wanted to. They just look so neat! I'd always be afraid of snapping the stem, though, being the clumsy person that I am.