Can a power supply be too powerful for a computer?

I have a 300W Power Supply and it's going out I'm pretty sure. I was gonna a buy a new one but I was thinking about getting like a 450 or 500w is it possible this is too powerful?

Basically I would say you can not be too powerful. Regarding PSU's that is.

This is a very good guide:

http://www.bleedinedge.com/guides/ps...select_01.html

What's a well known brand name I don't want to buy a cheap one that's gonna go out in a week or something from extensive gaming.

Originally Posted by PlatinumMoto

What's a well known brand name I don't want to buy a cheap one that's gonna go out in a week or something from extensive gaming.

I would recommend Enermax (http://www.enermax.com/english/index.asp).
My favourite PSU from them is the Liberty-series, gives you many plugs as well as 1-fan cooling (making it more quiet).