Linux distros have come a long way in the last few years. Up till the mid 2000s, you sacrificed a lot in using them, and required a pretty high level of expertise. Today, I think the user-focused distros are comparable in usability to the leading closed operating systems. The enterprise-focused distros are a bit tougher, requiring more knowledge (or willingness to learn), but on the other hand are generally safer. Many of them are good. The two I know most about are Fedora and Ubuntu (others may be equally good, or better for some purposes, but I just don't know enough).
What I use for server systems is Fedora. It's highly secure, generally very up-to-date, and fairly bullet-proof. On the other hand, it isn't always the easiest distribution to maintain. But it's what I would recommend if you are maintaining servers. But I would also recommend
I mainly use Fedora for desktop systems because I have to be familiar with it, so using it for desktops as well makes sense for me. However if I only had desktops, I would probably use Ubuntu instead (I keep a couple of Ubuntu systems - this being one - and they seem to require much less maintenance than Fedora). For personal systems, the decision whether to use selinux on ubuntu is more complex - you're trading off convenience for security. But if you're going to use your machine to access financial accounts, I'd turn on selinux (an even safer choice is to boot a system from a liveCD, and use it only for financial transactions - because it's read-only, even if you did pick up an infection in one session, it's guaranteed to be wiped again for the next).