The answer, of course, is none. It's a fallacy, because perfect security is impossible. If you want your computer data to be perfectly secure, then smash your device to pieces, run them through a blender, and drop the bits into volcanic lava.
With that said, we cybersec experts do use stuff. From this you can derive some sort of implicit endorsement. I use Windows, iPhone, and GMail, from which you can assume they are probably "secure enough".
I use an iPhone because it has excellent security. For all I criticize Apple's security, the fact is that they have very smart people solving the toughest problems. For example, their most recent operating system will randomize MAC addresses when looking for WiFi in order to avoid disclosing your identity. This is a security problem I've blogged about for years, and it's gratifying that Apple is the first company to tackle this problem.
If you do the right thing, such as locking your iPhone with a complex code, you are likely safe enough. If a thief steals your phone, they will likely not get your private secrets from it.
On the other hand, if you don't lock your iPhone, then the thief can steal everything from your phone, including things your phone has access to, like your email. That's the problem with "security endorsements": I as an expert can't help if you don't help yourself. Your biggest threat isn't the products you use, but you yourself. Your top threats you are getting easily tricked by "phishing emails", drive-by downloads, lack of patches, and using the same password across many websites. Choosing greater or lesser secure product doesn't really much matter in the face of bad decisions you make with those products.
With that said, there are some recommendations I can make. Public wifi, such as at Starbucks or the airport, is very very bad. Among the things I'm known for is demonstrating just had bad this can be ("sidejacking"). The safest thing is not to use it -- tether through your phone instead. But, if you have to use it, use a VPN. This encrypts your data to a remote site across the Internet, so that local people near you can't decrypt it. There are lots of free/cheap VPN providers. Another option is "Tor", which acts like a VPN, but also anonimizes your identity. These are a little bit technical and hard to use, but can make using public WiFi secure.
We experts know that the standard way of building web apps on the backend using the "LAMP" stack is inherently insecure. PHP, in particular, is a nightmare. Pasting strings together to form SQL queries is bad. Not whitelisting output characters is bad. If programmers just heeded these last three sentences, they'd stop 99% of the ways hackers break into websites.
Microsoft, Apple, and Google care about cybersecurity. They are really the only companies I can point to that really do care. Their problems stem from the fact that they are also popular, and therefore, the top targets of hackers. Their problems also stem from the fact that security is a tradeoff: caring too much about security makes products unusable.
Tradeoffs is why Android is less secure than iPhone. Apple limits apps to only those they've approved, whereas Android allows apps to be downloaded from anywhere. Android's policy is better, it gives control over the phone to the user rather than than the fascist control Apple has over their phones. But the price is additional risk, as users frequently download apps from dodgy websites that "infect" their phone with a "virus". Thus, if you want a secure phone, choose iPhone, but if you want a phone that you can control yourself, choose Android. Note that Microsoft makes technically excellent phones, but nobody cares, because they don't have the apps, so I don't mention them in the comparison :).
I use GMail. Google's web apps have the best track record of security, being the first to adopt SSL everywhere all the time. There are still problems, of course, but their track record is better than others.
As an operating system, I currently use Win7, Mac OS X, and Ubuntu (using Windows the majority of the time). I use them with full disk encryption. They are all equally secure as far as I'm concerned. I use Microsoft's Office, on both Windows and Mac, as well as their cloud apps.
Finally, I want to discuss the security community's historic dislike of Microsoft. It's not valid. It's always been a political dislike of Microsoft's monopolistic control over the desktop, and an elitist preference for things like Linux that aren't useable by mainstream. I point this out because I can't endorse the advice form security experts -- their advise is more often going to be political rather than technical.