Do you prefer Vertical scrollers or Horizontal scrollers?

Horizontal.
 
You normally can see more shit coming from the right with the screens being wider in length.

i like vertical scrolling better. my house only does vertical so i can't side scroll without pressing it in.

Vertical!!! Flipping your tv on its side ftw.

Definitely horizontal. Castlevania, Shantae, Contra and the like make Vertical just seem wrong.

Horizontal for sure.

Vertical for me. I'm a fan of all those Raiden and 1942 games. Einhander is a bad-ass horizontal shooter, however, and everyone loves Defender (besides me, ironically).

I love them both equally and won't be clicking into any of these Sophie's Choice shenanigans.

I guess I should have phrased the question better, I was mostly referring to shmups. As far as shmups go I personally prefer vertical but anything else and horizontal takes the cake.