For music, I'd recommend CDs that you are very familiar with. I often use Dream Theater 'Awake' and NIN 'Pretty Hate Machine'. For bass, since I like electronic music, I often use Crystal Method 'Vegas' and Junkie XL 'Saturday Teenage Kick'.
For DVDs of movies, I use Haunting-DTS, Titan AE and U-571 among others. I don't have any music DVDs so I can't help ya there.
For a CD with good bass material, Rickie Lee Jones', "Pop Pop" is good. If you are looing for a sub you may want to get the Delos label disc "Surround Sound Spectacular." It is a 2 disc set that is $17-18 that includes one disc of 5.1 music and one of tests, including bass tones (or Stereophile test disc 3 or an appropriate disc with test tones). I would not automatically presume that the subs are set up correctly in any store and it would not be a bad idea to play the bass tones while having a SPL meter in hand. At $35, the Radio Shack analog model will give you a rough idea at least and it will be of value in setting up your system.
The best advice I ever received on testing hi-fi was that you don't spend your days listening for frequency extremes, spatial positioning, etc - you listen to *music*. Accordingly, take along some discs which you've played occasionally but aren't your all-time favourites (long story, but this makes any differences between the new system and your old one all the more telling). Sit back, see which one gives you the most *pleasure* and buy it. And if it doesn't happen to have the biggest or best technical specs, what does it matter if it's what *you* like the best?
Acoustic vocal music, especially small ensemble jazz, can be very revealing in testing speaker performance. of course, if you are buying the speakers more for HT than for music, you will probably want to give them a stress test, too, I guess.
Livonia, MI USA
If you can get your hands on it, the Holly Cole Trio's version of I Can See Clearly Now has incredible vocals and a killer stand up bass that will definitely test any systems ability to reproduce bass properly.
------------------ My DVD Collection
Depending on the purpose of the speakers that you using for...
For orchestral music,classical or movie scores,try-
VIVALDI'S FOUR SEASON for the highs
HANDEL's organ works for the lows
BACH's BRANDENBURG CONCERTO for the mid and overall ambience and dimension
HANS ZIMMER's GLADIATOR,THE ROCK,CRIMSON TIDE and MI2 for bass
HANS ZIMMER's BACKDRAFT,GLADIATOR,PEARL HARBOR for highs
JAMES HORNER's COURAGE UNDER FIRE for overall
SARAH McCLACHLAN's ANGEL for mids and vocals
SAVING PRIVATE RYAN- BEACH ATTACK
AIR FORCE ONE- MIGS ATTACK
COURAGE UNDER FIRE
RULES OF ENGAGEMENT- VIETCONS ATTACK
...and others more