I use a free application called Spark, which lets me bind global hotkeys to arbitrary things, and in particular those things can be "bring up the topmost window of application X while leaving the rest where they are". I have it set up so that control-shift-h brings up Terminal, control-shift-c brings up Chrome, control-shift-f brings up Finder, control-shift-n brings up Firefox, etc., and for most of those I have "Bring [to] front the main window only" set. I use the hotkeys many times a day.
https://www.shadowlab.org/softwares/spark.php