"Merged duplicate thread"
1. That adapter is not any better or worse.
"Assuming" you want to plug the video in through an HDMI port on the TV, then you can grab one of the following instead of a purchasing two pieces - adapter and cable.
Adapter/Cable combined into one.
Before you buy that cable, you need to consider where you want the sound coming from. The mini-display port does not carry audio. Some TVs do not allow for separate sound input associated with any of their HDMI ports as they "assume" the sound is being carried on the HDMI cable.
Are you wanting to get the sound to the TV or to a separate receiver. If you want sound on the TV, will need to know the make and model of the TV.
2. The iMac G5 has a mini-VGA port,
not a mini-display port. You will not be able to plug the G5 into the TV via HDMI. You will need
this adapter and a VGA cable plugged into the "PC" (VGA - 15 pin) port on the TV if it has one.