i will not recommend one company more than other because it is not the company that makes systems secure, it is the people who work for the companies. same as if i say that restaurant is good. just because location near me has good cook does not mean that location next to you has good cook also. same applies to service from companies.
what
@poojatiwari mention is very true but it is not enough.
i will simply tell you this:
if you want to keep system safe then never place system on internet. if you must place on internet then it will never be 100% secure. every day there are new vulnerabilities found. apply every principle mentioned by
@poojatiwari but know that it is not enough. never leave any software configured with default configurations. if there is a configuration to be changed, then you must change it! do not expect software to be safe. use different software for different purposes. when you try to unify solutions, you depend on solution to be all inclusive and you will find yourself to land on your face when it fails (because it will). just as i say about having cook to be mechanic and mechanic to be doctor, this applies to software also.
always run latest security updates and patches but not always latest release of software. never use beta. if there is a LTS version, this is best. use software as it is designed. different software for different purposes. example: just because php can be own webserver does not mean that it is wise to use it. instead, use apache, or nginx because they are "application (usage) specific." just because nginx can block bad requests does not mean it is meant to be trusted as solution. use other intermediate solution. log everything and monitor logs for unusual activity. create jails so that no user can do more than what is necessary for its own purpose. block everything then allow only what is needed.
security is a practice, not a solution. what is secure for one system may be weak or too secure for another.
all of this and much more has been mentioned in various parts of the forum but clearly you do not wish to do your research! you just want others to share their own and dump into one single place. again i will tell you, there will never be just one place to find answers for this or any other generalized question. especially when people spend many years and there are thousands of books, multiple organizations, certifications, etc that all focus on this one specific but generalized topic. those who wish to exploit always lurk around the corner and monitor the same discussions.
do you know kung fu?
jackie chan and jet li are both great at kung fu. however, there are many styles of kung fu. jackie chan is great at drunken monkey but jet li's tiger paw is better. jackie chan's preying mantis is better than jet li's tiger paw, but jet li's white crane is far superior.
you remark about my repetitive "use the search tool" or "google it" responses. everyone wants to eat fish but no one wants to learn how to catch fish. you ask bullshit questions like where can i get fish, or how to cook fish. the strongest man is not the one with the most questions, it is the one who knows where to look to find answers.....