I have my tigers in with a Redtail shark and they work pretty well together... If anything the shark ends up chasing them around.
From my experience, tigers would be fine with one of the more aggressive gouramis such as the blue, opaline or gold as they themselves can be labeled one the "meaner" or more aggressive fish in a community (especially as they get older).
A dwarf or honey gourami would definately get worked pretty well by the tigers though.
Tiger barbs can indeed be very aggressive at times but I disagree with them needing to be in a species-specific tank. All you need to do is keep them in decent numbers and place them with other species that will either not let the tigers push them around, or are simply not interesting or fun for them to chase.