Here's a recent thread:
http://www.karaoke-forum.com/viewtopic.php?t=18400
Here's my take.
Sound Choice is good for most things, and is by far the best for most songs that depend on guitar. It has more really strong tracks, and a lower percentage of clinkers, than any other brand.
Chartbuster is real good for country, and for 50s / 60s oldies. Not so much for 70s and 80s with strong guitar lines -- their lead guitar is substandard. If the song depends on pedal steel and fiddle, as much country does, Chartbuster is usuallly the best.
Pop Hits is very good, very authentic general music lines. They also have some excellent lead guitar. I consider them to be underrated -- if they had dot-leaders I would put them right up with Sound Choice. They are often my preferred manufacturer if I have multiple copies of a track.
DK is very good in general sound across a wide range of music. But many people dislike three things -- 1) possible one-step key change on a song that most people have trouble with, 2) the pan flute melody lead, and 3) no coverage after 1996 with only about 1600 songs available.
Zoom is OK, but to be honest I don't get people putting them up with Sound Choice. Perhaps on their newer stuff. They have good lyric production values.
SBI is up and coming. While they aren't SoundChoice quality, they are making lots of songs and they are generally pretty good.
Priddis (and their Lost Classics) is pretty darn good. Music is often excellent, lyrics values not quite as much.
Legends/Sunfly is strange. Their sound is not much like the original many times, but sometimes that is a plus for singing the song. Example --
Cherry Bomb and
I Got A Name. Sound Choice and Chartbuster are both "better" in the sense that they are closer to the original, but the Legends is much easier to sing to and sometimes sounds better (perhaps due to hosts not turning up the under-modulated SC/CB versions). I consider Legends to be upper second-tier.
Panorama produces Big Country, Big Hitz, etc. I find their stuff to be decent most of the time. They are one of the ones often used in....
Supercore is a compilation brand. They use Panorama, old Pioneer, Nutech, and even some SoundChoice.
RadioStarz is unusual. They have excellent music quality and poor lyrics production. Accuracy is generally great. Their Steely Dan disk is one of the best overall disks I have ever heard.
Party Tyme is pretty decent. Not outstanding, but usually not *bad* like ...
Monster Hits is better than
Music Maestro, but both are very uneven in their quality. Often poor lyrics syncronization. Music Maestro has a few decent things, but overall they have a high percentage of clinkers where you finish the song and think "what was *that*?"
Amerising is often rebadged Sound Choice. What else it is I don't know.
Brands I don't like at all:
StarDisc (often *way* off),
Top Hits Monthly (poor production, very poor guitar playing, very uneven),
Backstage
Poor-quality brands with some redeeming value:
Sweet Georgia Brown (very poor lyrics, overmodulated, but often surprisingly good sound),
Song Factory (good sound),
Nutech (decent overall sound production but terrible lyrics sync and presentation)
Summary: Here are the tiers as far as I am concerned
First tier: Sound Choice, Pop Hits, Chartbuster, DK
Second tier: Zoom, SBI, Legends/Sunfly, Panorama, RadioStarz (*Starz in general), Supercore/Pioneer
Third tier: Party Tyme, Dangerous, Song Factory,
Junk that is very uneven: Top Hits Monthly, SGB, Monster Hits, Stardisc, North Star, Country Karaoke Classics, Backstage
Stuff I know little about but have a generally good impression of: Priddis/Lost Classics, Mr. Entertainment
Ones I know nothing about: Karaoke Kurrents, Karaoke Bay