1. Melody Gardot - "My One & Only Thrill" - excellent album for female vocals, instrument detail and reproduction. Marvellous album with gorgeous vocals and instrumentation.
2. Queen - "Innuendo" - surprisingly poor production in my view: the first track demonstrates the contrasts between excellent acoustic guitar and vocals (middle section) and the horrible mess that is the muddled sound of the drums, backing vocals and other instruments on the rest of the track. If a system can improve what you hear, it has to be good!
3. The Lens - "A Word In Your Eye" - the combination of synth high and bottom end frequencies on the opening track will test a system's ability to cope. There is a good range of acoustic guitar, electric guitar, etc, to demonstrate a system's ability to convey them at their best.