Kailh's reputation for quality is gradually improving after a somewhat rocky start. My vague impression from reading Google Translated sources is that, in Asia, they're slowly coming to be regarded as a more reliable choice than other "domestic" (i.e. Chinese) switches, if also a little bit more expensive. Of course, as with any switch, if you get it in a keyboard that, itself, has poor QC or design flaws, you're going to have a lot of problems.
Outemu switches are very cheap, but they seem to do the job well enough for many people. The blue ones also win some fans for having a more pronounced click than the equivalent switches from other manufacturers.
I don't think one should necessarily assume that Gaterons are a higher-quality switch. They do have a lot of fans, but their support comes mostly from their feel rather than any information about long-term reliability. Some people have run into trouble with them, at any rate.