Which flavor Linux or Unix to go with for your Quant software solution?

Which flavor Linux or Unix to go with for your Quant software solution?
This is one of those tough questions I always struggle with. It is quite easy if you ask me. I am always the kind of person to focus o n the top three to five choices. In this case, I will only focus on three.
1. If you want total free and the most popular. It does not take an idiot to go with Ubuntu. This is one very stable and hugely popular Linux flavour I would highly recommend. You also have the choice of a desktop version or server edition depending on the enterprise level you need.
2. If money is no object, I woud go with Red Hat. Even though it is commercial based (paid), you cannot go wrong if you have certain service level agreements needed or enterprise level support from a reputable company. Everything is based on a subscription fee on a per server/CPU basis. It is the number one choice as even Goldman Sachs was an earlier paid client of theirs.
3. If you really cannot afford a subscription fee on an annual basis, I would recommend the next best alternative which is CentOS. It is supposed to be one hundred percent compatible with Red hat. The best is that it is open source meaning of course, free. No one can wrong with that. From what I see beng on the developer and user list of Red Hat, there are some highly intelligent technical people that can help you out for any needs you might have.
I hope this gives a quick synopsis of which flavour of Linux you should go with. I can tell I would promote CentOS if you want to stay on the same level as Godlman Sachs. Even my older client were using strategically for all Linux installations they had.