Probably too late but hi again!

Although I don't have any experience with Objective-C, it is widely used for a reason. (I completely disagree with BillyRuben's above post and am a firm believer that every programming language has its merits, none of them are perfect and that absolutely none should be dismissed immediately, without even an investigation. Not being open to new ideas (and thus opportunities) is a surefire sign of a mediocre programmer. :P)
At this point, if you have the experience, it might be worth spending a lot of time with one language but dabbling around in several others both to gain experience in programming and the involved thought processes in general and to learn to think in different ways. What I see from you now is a strongly object-oriented approach, but the way that makes you think is not going to help you in an environment where procedural or functional programming is dominant. To be a good programmer, diversity of media is essential.
Just something to think about.
I'd recommend scheme and straight C for you to dabble with, and Objective-C if you're planning on Mac development. Scheme because it's functional, the syntax is somewhat of a throw-off from what you're used to, using an interpreted language makes it easier to see where you've gone wrong and fix your mistakes when you make them, and it's just plain fun. C because the syntax is familiar but you'll be working much more closely with pointers (if you were working with them at all in C#) and you will need to approach problems in the same way as a procedural programmer would.
Programming truly isn't a "one language and you're set" deal. To be really successful you will need more than that.