Redgate SQL Prompt which is one of their tools I use on a daily basis - it provides intellisense for writing SQL queries as well as a lot more - it has some very nifty options for splitting tables, smart rename which you can use to rename a table column for example and it will do this for all objects which reference the column changed.
Format SQL does just what it says on the tin - it formats your SQL based on formatting options that you as the user define.
Find Invalid objects looks through your database and will show you any objects which have became invalid - say a column is renamed by a user but they forget to changed the stored procedures that reference the old column name - this tool is your new best friend.
These are just some of the options available in SQL Prompt - the number one thing going for this tool is productivity - you can write SQL queries much faster.
For a 14 day free trial:- http://www.red-gate.com/products/sql-development/sql-prompt/