Yep you really need delve into the setup of the TV. As said avoid screen setting like vivid, dynamic, showroom etc. Obviously depends on the make of TV.
Also getting the setting correct for things like gamma make a difference.
Last new TV I bought approaching 2 years ago took me about 2 months to get tweaked to best settings and included a few search's on the web looking for info on the best way to set it up.
edit: many sets have a sharpness setting , don't turn it up it usually needs turning down from default value.