The SQL Toolbelt Essentials suite helps speed your T-SQL development with SQL Prompt, which has much better text completion than SSMS' built in IntelliSense and saves tons of time by formatting your code just how you or your team like. SQL Compare will help you do diffs of your environments and sync them, providing a script that you can tweak and run. I've also saved lots of time with SQL Data Compare when dealing with lookup tables. Review collected by and hosted on G2.com.

The only downside is that it's not free, so I'm always having to convince my organization to pay for licenses, and sadly, I often fail in that regard. The cost is well worth it, though. Review collected by and hosted on G2.com.