How to choose a good power supply unit?

[Exodias3219]

Hi! Me and my friend scheduled a visit on a local computer parts warehouse (this warehouse sells second hand but in good quality) and I'm planning to get a new power supply unit. This warehouse doesn't give advice to its customer (it is NOT noob friendly), therefore you cannot ask "which one of these power supply unit is much better?" I'm really concerned on how to read the power supply labels which one should I look after, which one shouldn't. Thanks for your help

 

[Exodias3219]

I'm currently reading this post : http://www.tomshardware.com/faq/id-1927916/power-supply-101-understanding-power-supplies-selecting-job.html

but any advice or suggestions would be a great help

 

[CTurbo]

This thread should help. http://www.tomshardware.com/forum/id-2547993/psu-tier-list.html

The tier list is not perfect, but it's a pretty good start. We typically only recommend stuff from tiers 1 and 2.