SQL Server 2005, plan cache, becoming bloated with excessive amounts of adhoc queries with a usecount of 1, crashing the server.  64 Bit SQL with 32gb of RAM.

Ran some queries to determine which database was causing the most adhoc cache plan bloat, than we set the force auto-parameterization on.

-- Get the size of the Plan Cache (CACHESTORE_SQLCP is non-SP and CACHESTORE_OBJCP is SP)
SELECT (SUM(single_pages_kb) + SUM(multi_pages_kb) ) / (1024.0 * 1024.0) AS 'Plan Cache Size(GB)'
FROM sys.dm_os_memory_cache_counters
WHERE type = 'CACHESTORE_SQLCP'
OR type = 'CACHESTORE_OBJCP'

-- UseCounts and # of plans for Adhoc plans
SELECT usecounts, count(*) as no_of_plans
FROM sys.dm_Exec_Cached_plans
WHERE cacheobjtype = 'Compiled Plan'
AND objtype = 'Adhoc'
GROUP BY usecounts
ORDER BY usecounts

Use this DMV query to find the offenders:

-- Find the ad-hoc queries that are bloating the plan cache
SELECT top 1000 *
FROM sys.dm_Exec_cached_plans
CROSS APPLY sys.dm_exec_sql_text(plan_handle)
WHERE cacheobjtype = 'Compiled Plan'
AND objtype = 'Adhoc' AND usecounts = 1
--AND size_in_bytes < 200000
ORDER BY size_in_bytes DESC

-- Setting the PARAMETERIZATION option to FORCED
ALTER DATABASE [adtempus_DTSR] SET PARAMETERIZATION FORCED WITH NO_WAIT
GO

-- Setting the PARAMETERIZATION option to SIMPLE (default)
ALTER DATABASE [adtempus_DTSR] SET PARAMETERIZATION SIMPLE WITH NO_WAIT
GO

-- The current setting of this option can be determined by examining
-- the is_parameterization_forced column in the sys.databases catalog view.