I know most of you have them through GOG.com (including me) but if you want physical copies of each series, well here they are.
Gabriel Knight Trilogy
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220621809533&ssPageName=STRK:MESELX:IT
Tex Murphy Trilogy
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220621817504&ssPageName=STRK:MESELX:IT
Gabriel Knight Trilogy
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220621809533&ssPageName=STRK:MESELX:IT
Tex Murphy Trilogy
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220621817504&ssPageName=STRK:MESELX:IT