Each Giga Pet plus offers multiple pets / characters.  The middle button on them all is a light.  They all have really nice graphics and sound.  Supposedly they also respond to voice.

Looney Tunes

6 characters. Keep as many happy as you  can!

Small Soldiers

Keep as many as you want also.

Giga Circus

Another one where you can choose as many as you want to keep happy.

Giga Farm

Chose from 4 pets and three crops.

Giga Pound

Has 8 dogs

Rugrats

Another multiple choice to keep as many happy as you want.