This thread looks like a good old-fashioned urinating/popularity contest (which is fine I guess). I don't know the answer, but the answer will be in part on what exactly do you mean by reliability?
1. Reliability out of the box, and/or when well-maintained during the first 10,000 of use kind of thing (i.e. Best design/best inherent reliability), or
2. Reliability under adverse conditions such as under freezing temperature or with mud/sand/grit in and around the gun (because this may or may not be the same answer as to the answer to question 1).
3. Reliability under tortuous, long-term conditions, 20k, 30k, 40k, 50k, 100k +, and furthermore, during regular interval mag spring changes and other parts swaps, or straight, flat-out, no replacement torture?, or
4. Some total reliability factor based on an over composite of all 3?
The answer also may be brand X in 9, brand Y in 45, and brand Z in 40, and then a different answer for each of the 4 above. In any event, I don't think anyone has done a comprehensive, scientific, repeatable, regression-analyzed experiment on this stuff, so it's probably all speculation anyway, although I'm sure the answers you've received are roughly correct. My wild stab would be CZ, Sig, or HK, but I don't know. I will say this, however, which is a side subject, that ANY pistol in the caliber 9x19 (luger, parabellum) is going to on average, be more reliable than other chamberings, simply because the cartridge is both short and tapered. The 9x19 is the king of reliability, IMO. But with some brands, we may be talking about 1 round per 50k rounds that ftf with 40 that wouldn't with 9, etc. So it's negligible with a quality brand. However, if ultra reliability is your main goal, get ANYTHING of high quality in 9x19. That doesn't answer the question, but...