then other than apple, who is the most reliable? Thanks.
OK: once again *:
All RAM that is 100% compatible with the Mac, will run at precisely the same speed. So there is no performance difference between brands.
There have been a number of reputable sellers mentioned: Crucial, OWC (macsales.com) and Data Memory Systems (datamem.com) are the most often recommended US sellers. All offer lifetime warranties.
You can't really say that one brand is more reliable than another. You are going to see about a 1% infant mortality rate on any RAM. The difference is in how well the seller treats you... do they send a replacement quickly, and in advance of you sending in the bad one? or will they insist on you sending the RAM back to the manufacturer and waiting for replacement?
You can't go purely by brand name either, because each brand has dozens or hundreds of different models. Also, some brands have "value" or generic lines of memory that are not the same modules as their branded memory.
I prefer to recommend a company that tests and guarantees Mac compatibility, and has a no cost replacement or return (no shipping charges) if the RAM arrives DOA. I think buying PC generic RAM (without explicit Mac support) to save 2% - 5% in the cost is foolish, as is buying from a PC discounter who will charge restocking fees or shipping to take it back. But that's my opinion.
(* we have had oodles of threads on RAM, we do this at least once or twice a week. Searching the forums is highly recommended.)