A lot of different things. But I know better than to get into a discussion about anything Microsoft-related with you, so I'm not going to bite.
I won't jump, promise. I genuinely want to know
Fine, since you promised. These are just the things that bug me most.
My least favorite thing so far is pointers, though. Having to declare variables as "fixed" indicates a fundamental problem: they're trying to add a low-level paradigm to a high-level language, and end up with ugly constructs like that. It doesn't have a good feeling to me.
I also hate operator overloading. To me, a + should always add and a << should always left-shift. C# provides operator overloading, which is something I can get over. However, when using, for example, delegates, you add all your events to your delegate with + and remove them with -. That kind of thing just isn't right, to me. Then when you want to find out if it's empty, you compare it to null. That's just confusing, it took me awhile to figure out how a non-reference variable could be null. In my opinion, it's exactly why operator overloading is bad.
Another thing I don't like is that they .. damnit, I got an email and left for 10 minutes, so I totally forget what I was writing. Ohwell.
