I might be a bit biased, but C# is just so nice to work with.
The syntax is very clean and simple. There isn't a lot of freaky stuff like in Perl.
I think it's a good choice because it's highly productive
over a very large range of things.
Also, there is a HUGE amount of code and support for it out there. http://www.codeproject.com/
-- Great site.
Worrying about memory issues is really not a productive use of your time. C/C++/Objective-C are simply slow that way. Now, there are things where you really need pointers, but not usually. Managed code is simply a wonderful thing.
Later on, you can look at Mono. You WILL miss Visual Studio though. Make no mistake, Visual Studio is the Death Star, and many other IDEs seem like rocks and sticks in comparison.
MonoDevelop is pretty good though. It's not VS, but it works well enough. Don't start there though. It's not the massive productivity tool that VS is.
The Mono team is very good and they really think through a lot of things in Mono, so it's definitely something to get into once you are more comfortable. Don't start with it though.
I prefer strongly-typed languages though, so I would shy away from languages like Python. Both have ups and downs. I just find strong typing is nice to work with.
But at the end of the day, I think the most important thing is the IDE. A nice IDE will help you get things done no matter the language.
.NET, to me, seems like the right way to approach things. It's faster, easier, and more productive. And you can choose any language you want just about. Don't count on having Erlang# though or Lisp#. But you can do functional programming with F# if you like.
There are 2 basic popular IDE types: the VS style ones, and the Eclipse style ones. The Borland, or whatever they're called now, IDEs are like VS. Xcode is sort of like Eclipse.
I'd recommend having a look at Eclipse at some point. You might like the way the UI builder is separate.
Have fun~! Programming is a pure joy!