Looooooooooooove the Karaoke...
I started off with an 'all in one' set from 'well known auction site'.
This included a DVD / CD-G player with microphone inputs and echo effects. It came with 2 DVDs of karaoke songs, 2 x wireless microphones and songs-choice book.
I then purchased several more CD-G discs.
Now I use my PC or Netbook and have stored my collection as MP3+G which is the MP3 equivalent for Karaoke files. I use Locate32 to search through my collection by song title or artist. And use an old version of Winamp with the CDG Plugin to play the files.
In between all that I purchased a DJ rig, 2 pa speakers and stands, lighting and a huge sub, mixer, mic echo effect and more wireless mics. I got carried away.