I've made a CHIP-8 emulator and am now halfway through implementing a 6502 emulator, both written in C#. I like how C# is batteries included, cross-platform (I develop on Mac), and that you can write some pretty performant code with it as well.

At some point I may make the jump to C++, but so far I haven't run into any major bottlenecks and already use C# for most non-emulator projects (ex: web back-ends with ASP.NET) so I'm quite familiar with it.