Select unique records

I have a query that returns the results I want, but I need to get just unique records, but still return 25 records after dedupe.

SELECT TOP 25 [StartTime], [EndTime], [CallerURI], [CallerIPAddr], [CallerSubnet], [CalleeURI], [CalleeIPAddr], [CalleeSubnet], [GatewayMSPair] FROM [QoEMetrics].[dbo].[QoEReportsCallDetailView] WHERE [QoEMetrics].[dbo].[QoEReportsCallDetailView].[GatewayMSPair] IS NOT NULL ORDER BY [StartTime] DESC

What's the best way to dedupe but still get the right number of records?

I'm not a SQL guy, so speak slowly and use small words.  :-)