I started looking at F# because of .NET Core, and I'm really liking it. I currently use Giraffe in a project, but I'll be switching it to Saturn soon (which uses Giraffe under the hood). And I've identified a potential use case for using Fable on some already written server-side code. Ionide is great, Neptune (F# debugger for VSCode) works well, and they both are maintained by the same person as Saturn.

Rider also works pretty well with F#, which is nice if you prefer the JetBrains IDEs.