I guess small would depend on whether you want a boxy standmounted speaker, or something thinner but long like an on-wall speakers (the Martin Logan Frescos fit this category). In general, the standmounts will work very well and plenty of them can take you down to about 50 Hz, which is about how low you want your speaker to go if you plan to use a subwoofer crossed over at 80 Hz.

Plenty of great suggestions so far, and I would add the Paradigm Studio 20 v.3 or Signature S2, Sonus Faber Cremona Auditor, Vienna Acoustics Haydn, Monitor Audio GR-10, Energy Veritas v2.2, and the PSB Platinum M2. For on-wall speakers, in addition to the Martin Logan Frescos, look for the Vienna Acoustics Webern and the Vandersteen VSM Signature.

Others have recommended panel speakers, and I know that Magnepan makes some panels designed for wall mounting, but most of the ones I've heard over the years don't really come to life until you push them out a few feet from the wall and they're bigger than you're probably looking for.