Speakers that are specifically designed to be placed very near or on the wall are not that common. North Creek Music makes three that are, at different price points. IMHO they are all bargains and the top of the line is a remarkable high end speaker. They are sold as kits but North Creek is associated with a first-class cabinetmaker who can supply the enclosures or sell assembled models.http://www.northcreekmusic.com/
The reason that speakers need to be designed specially to work well near a wall has to do with the megaphone effect. Sound waves at the lower frequencies tend to spread out in all directions. When they meet the back wall they reflect back and reinforce the waves coming out of the front of the speaker. Depending on pitch or frequency, some of these waves will cancel each other out. Others will reinforce. So you get a frequency pattern or response that is not even, it favours some notes and not others.
A speaker that works near the wall is designed to work with, not against this phenomenon.
A while ago I gave my sons each a pair of bookshelf speakers. Then I realized there was no room for stands in their bedrooms and the speakers would have to go on the wall. This model has a rear port to tune the cabinet for bass. I found a wall mount that kept that rear port as much as five inches from the wall but it's still not enough. Whenever they play loud music it goes boom, boom, boom on certain notes. It gets tiresome. I am saving to buy new speakers, not for the boys (they don't care) but for me.