Rider

JetBrains Rider is a new cross-platform .NET IDE based on the IntelliJ platform and ReSharper.
Supports most .NET project types

Rider supports .NET Framework, the new cross-platform .NET Core, and Mono based projects. This lets you develop a wide array of applications including .NET desktop applications, services and libraries, Unity games, Xamarin apps, ASP.NET and ASP.NET Core web applications.
Feature-rich and fast

Rider provides 2000+ live code inspections, hundreds of context actions and refactorings brought by ReSharper, and combines them with the IntelliJ platform's solid IDE features. Despite a heavy feature set, Rider is designed to be fast and responsive.
Cross-platform

As well as running and debugging multiple runtimes, Rider itself runs on multiple platforms: Windows, macOS and Linux.