Please note: these lists may not reflect your own personal experience. Note that not all models within a single brand label are of the same quality, and these are averages for the entire model range of brands, not just specific models.
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Here's a categorized list of brands by quality grouping according to performance and reliability based on reputable, cross-brand reviews listed in the External Links. Some brands release top-quality models, some just release value-line models, and others shouldn't be releasing models at all! To make things worse, some generally high-quality brands cash in on their reputation by making a cheap (in all senses of the word) line.
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A single-rail design isn't itself a sign of a low-quality PSU. This is technically in violation of the ATX-power-supply specification but has not proved to be a safety problem in practice, and is preferred by many people. (This may be a clue that the PSU is incapable of delivering its full-rated capacity.) An even cheaper alternative, which has become quite popular, is to eliminate all of the safety circuitry and produce a "single-rail" power supply that can deliver all of its output on any wire. A cheaper alternative is to provide just enough rails to total the overall capacity, which makes it difficult to use all of a power supply's capacity. A good power supply will make that easy by providing rails totalling much more than the total PSU rating.
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(But there's the advantage that the wires aren't hidden in walls, so they're cooled better, and you'll smell it if something starts burning.) This, however, makes connecting the PSU more complex in addition to not overloading it overall, you have to avoid overloading each rail, or it will shut down. The relevant safety standard requires a 20A limit, which is quite generous, given that the wires are smaller than those used in your house to carry 15A. Just as your house's fuse box includes both a large main breaker and a smaller circuit breaker per circuit to ensure the smaller-branch circuit wires do not overheat, high-capacity PSUs divide their output into multiple "rails," each with a smaller current limit.