SQL Sentry provide great diagnostic tools and a great event management solution. If you are running multiple servers and want a view of what runs when and where this is the tool for you.

They also recently introduced a SQL Server Analysis Services performance tuning product, there is nothing in the market that does the same and by all accounts is a very good product

Hyperbac is the easiest to use backup compression software. Its different from the other SQL Server backup compression products because it isn't a VDI based solution, but sits at the operating system level. This means that you can compress ANY file using hyperbac. This is especially useful when dealing with large files you are passing between systems. This can be compressed automatically by Hyperbac without the need for a seperate compression stage. They also have an online version of their product, which allows you to read and write to compressed files. This means you can restore production databases to UAT and pre production without the need for the full space requirements of the production database.

Redgate are the SQL Server tools company. They just make your life easier. From SQL Compare and Data Compare to SQL Prompt they will make your life as a SQL Server professional much easier.

Quest have a suite of products for SQL Server. The most intersting ones are the peformance analysis tools. Foglight Performance Analysis for SQL Server is a stealth monitoring product that is able to collect information about your SQL Server systems with little impact on your SQL Server systems. Spotlight® on SQL Server Enterprise is an operational tool for monitoring your SQL Server systems.