Let’s work together on a canonical answer.
Native Apps
SQLPro for MSSQL
Navicat
Valentina Studio
TablePlus
Java-Based
Oracle SQL Developer (free)
SQuirrel SQL (free, open source)
Razor SQL
DB Visualizer
DBeaver (free, open source)
SQL Workbench/J (free, open source)
JetBrains DataGrip
Metabase (free, open source)
Netbeans (free, open source, full development environment)
Electron-Based
Visual Studio Code with mssql extension
Azure Data Studio
SQLectron
(TODO: Add others mentioned below)
The Java-based Oracle SQL Developer has a plugin module that supports SQL Server. I use it regularly on my Mac. It’s free, too.
Here’s how to install the SQL Server plugin:
Run SQL Developer
go to this menu item: Oracle SQL Developer/Preferences/Database/Third-party JDBC Drivers
Click help.
It will have pointers to the JAR files for MySQL, SQL Server, etc.
The SQL Server JAR file is available at http://sourceforge.net/projects/jtds/files/