Power Supply Manufacturer TOP 10 (or TOP 5)
Here's something you might not know. Most companies that sell power supplies don't actually make them. They slap a sticker on someone elses unit and sell it as their own (commonly referred to as "rebadged"). While many of them have their own features added to try and niche out a spot in a crowded market, this usually doesn't hurt it's performance and might even improve it functionally, not just add shiny eye candy. Many though, it's just eye candy. And many do absolutely nothing... they just slap a sticker on the side.
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#1a
Topower
(some TTGI - Super-Flower, OCZ, EPower/Tagan, RaidMax, Vantec, ACI)
#1b
FSP - Fortron Source Power
(Fortron, Sparkle, Cooler Master*, Zalman, Aopen)
#1c
CWT - Channel Well Technology
(Antec, Lead Power, Enermax, Xclio, Turbolink)
While these top three encompass more than the re-badges I've named, you can usually bet on a solid performer if you pick one of them. It's highly debatable which are better than others, of course. But all in all, everyone has had pretty good experiences. Not suprisingly, they are priced accordingly. None of them in the 400W range are going to be under $50. If your power supply is one of the above, chances are you can trust both the unit itself and it's claims on wattage per line.
#2a
Sea Sonic
#2b
Wintech
(Ultra X-finity)
#2c
Acbel Polytech
(Stateside, just the Cooler Master True Power)
Same with these, a bit more esoteric. If you can afford a Sea Sonic these have the best efficiency of any consumer switching PSU for computers. You'll pay for it up front, but your electric bill will be less in the long run.
#3a
Sirtec
(Chieftec, Enlight, ThermalTake, High Power)
#3b
HEC - HeroIchi Electronic Co.
(HEC, CompuCase)
#3c
AMS - American Media Systems
(Mercury)
Here you start finding dissention in the owners. Some claim it's the best in the world, some wouldn't let their dog run Windows 3.11 on one. Some of them have great reputations (TT & HEC) but the problem is a "squeaky wheel" one - it's hard to know just how good/bad things are when only people with problems post.
#4a
Youngyear
(Aspire, Logisys, MGE, Ultra X-Connect, Rosewill)
#4b
ATNG
(Coolink, CoolMax, Rosewill, StarTech)
Now we're into budget territory. Maybe it's just a quality control issue; some people love them but most hate them, and from bad personal experiences. I personally wouldn't touch them. They should work, but no one will be suprised if it smokes itself and takes your motherboard with it. They rarely come close to what their ratings state, very poorly constructed. (but usually colors or chrome and UV sleeved and colored Molex's and LED fans!) These for the most part are toys, although you might get lucky. Not all of them are, but it does take more effort in sifting through them than it's worth.
#5
CRAP!
(L&C, Deer, Allied, Eagle, CodeGen/Foxconn, EverPower, Maxpower)
If you believe one of these things will power your computer, I have a 7-band underdash amplifier/equalizer that's 250W+250W that I'll sell you for $5. You'll love it. Really, if you have one of these supplies, don't mention it to us. Just silently toss it out and buy one in the #1 category.
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Don't say about anything without a thorough enquiry.
I think I have confused the word "Caps". 
Very sorry for that.
