A bit late to the party, but TeXstudio works well on a whole host of platforms, so it’s what I use most of the time. (Note: I also use Sublime Text for simple documents, but it’s not FOSS)

I’ve heard Emacs and Vim have a nice workflow for TeX as well, but I have yet to try either out.

A bit slow on the roemy side here, but I really like LyX. It’s not for everyone. Purists typically don’t like it, and that’s fair, bit it’s made life very easy for me, also in collaboration.

While I have Tex installed on my machine I always find myself going back to Overleaf. It’s full of useful templates and cloud storage really make a case for getting started fast.

I found TexStudio on the pop shop and I have been liking it. Before that I was just using vim with a few plugins.

Emacs. It takes a steep learning curve, but it’s been worth it.