In the ultra-compact category, I tend to enjoy the Mark and Daniel Maximus Mini. For just over $1200, this speaker is extremely resolving, sports great imaging, great build quality, good looks, and can deliver a sound that's far larger than its small dimensions would suggest. If you like sparkle in your treble with warm mid-bass, you may very well like the Mini's. They do love their power though, so I'd try to give them a minimum of 30 watts of good clean current.
In the ultra-linear category, I would second the ATC recommendation. Although the model SCM-12 pushes the envelop the definition of 'small', ATC's are very "tell it like it is" speakers and are more apt to reflect whats being fed through them. They are also quite dynamic speakers for their size and sport a slightly more forward presentation. It's a great option for those who like a more 'live' type of sound that is also very "tell it like it is".
In the compact / full range category, I would look at the Guru QM-10's. These compact Swedish speakers are pretty friendly when it comes to room placement. Despite their funky size, they can throw out a good sound-stage and work well in nearly all room situations. I'd advise pairing these speakers with linear (not warm or overly colored) sounding electronics.
In the compact / Great value category, the Lenehan Audio ML1's get my vote. They are about as well rounded as it gets. Non fatiguing (yet still very detailed and airy) treble, sublime midrange that will make a Spendor blush, exceptionally tuneful bass, and they can go louder/cleaner than anything mentioned here. They truly sound more like floor-standing loudspeakers than compact monitors. A great buy at just over $2200.
Finally, my favorite compact monitor in the "all around" category would be Totem Acoustic's 20th anniversary loudspeaker, "The One". They are a bear to break in and to position correctly in a room, but once you get everything set up right, The One's do some things that small (and semi-affordable) monitors shouldn't do. Insanely holographic, quick, and tonally spot on, they also contain great dynamics and bass extension. I'd advise pairing them with warmer components (such as Bluecircle, Naim, or any good tube amp) to get the most of them. Again, they aren't the easiest speakers on planet earth to work with, but the efforts can be well rewarded when you get them set up correctly.
Just my meanderings. Good luck in the hunt! There are tons of great options out there!
