Speakers Against Side Walls

I have Allison One speakers and I'm wondering if there are any other speakers out there that are designed to sit directly against a wall.

Sure, they're called "on-wall" speakers. Several companies make them. Some, I would suppose, with more success than others. Do a google search for "on-wall" speakers.
Maggies or Quads both work well very near the side wall.
Take a look at Audio Note AN-K/J/E speakers. They are very high sensitivity speakers and are designed to be placed against the walls.
Carolina Audio speakers are designed to be placed very close to walls.

How about some K-horns...directly against two walls.

If you want speakers that are designed to be placed on the wall, I would guess -- without having auditioned any of them -- that there is some craft involved with designing speakers so they can be placed against a wall and still sound good.

Another point might be that whether or not speakers will sound good when placed against the wall depends on the room, the preferences of the listener, etc.
Gradient Revolutions, which use a dipole bass system and controlled directivity in the midrange and highs, work quite well against side walls but don't put them in a corner. While they are not designed specifically to go up against the side walls, their radiation characteristics do work quite well with such placement.

The Gradient Evidence uses a more conventional bass system and can be adjusted to work well up against a single wall, but again corner placement isn't advised.

Full-range dipoles such as Quads, Maggies, Sound Labs, and Martin Logan CLS also work well up against the side walls. Disclaimer - I peddle Sound Labs and Gradients.