Bent billiard, bent apple, bent egg are all pretty much tied for first place with me. Once in a while, a straight billard.
A few weeks ago, I saw an ad on this site for a Radice bone-colored Oom Paul, and I fell in love. I'm generally not that crazy about Oom Pauls, but this one was gorgeous! (I'm glad the merchant's website didn't actually sell that particular pipe, because it would have been way over my budget.)
And I always prefer a smooth tapered stem.