4 ohm (or 6) Bookshelf speakers. Pass Labs 30.8

It stays in class A at it's published rating.  Somewhere above those ratings it goes into A/B and continues to 130 and 195 wpc at 1% distortion.  Best thing you can do short of actually testing the amp with speakers is to read all the reviews of the 30.5 and 30.8 and see what speakers that used with them.  Unless your listening room is cavernous and you intend on playing to concert levels then the 30.8 will push most any bookshelf speaker you find to "reasonable" levels.  

@mplstereo: i have the xa30.8 and it sounds good driving 8 ohm loads. However, when driving difficult 4 ohm loads it becomes a whole new amplifier. I much prefer 4 ohm speakers with mine. I have had amazing success with the elac uni fi or adante range. For the money those uni fi speakers amd this amp are amazing.  

I have TAD ME-1 and technically they are bookshelf size although I think they come with the stands. The sound is incredible.

Jackd,
    Found a hometheaterhifi review that compared the 30.8 and the x150.8, and it really secured my interest in the xa30.8 over the x150.8.  Also I did follow up with reviews comparing 30.5 to the 30.8.  This also explained the class A and AB for both and bumps with what your saying.  This has been very helpful.  My listening levels are low.  I enjoy long hours of listening after work, while relaxing, and reading online.  Rocking out for me would be volume loud enough just to the point where I wouldn't hear a person speaking from 5 feet away or so, rarely.  I was able to get enough volume out of my Bose mini when I had that, those little rechargeable ones.  :)  

    Plowed through reviews, did see a lot of identical speakers among listeners, most were panel or floor, and few bookshelf (which partly worried me) but now that I have learned I have more freedom then I thought I did with bookshelf's, I'm not as concerned.    Maybe most folks that have these amps have more room in their home for larger setups so bookshelf's just are not as popular for that reason?  No matter.  

   Thank you for helping clarify this stuff.  Now I feel like this amp is way to good for me!  Kidding.  

Synergy between amp and speakers is paramount. If possible, audition your amp with prospective speakers. Some combinations work well together and others not so well.
You didn't mention your price limit? In my system I use a NAD integrated with a pair of PSB Imagine B's ($1000/pr). Synergy is very good with NAD and PSB. Do some research and you may find a good match with your amp.