There are more than enough posts on this subject. All subjective ... "harsh" ... "comfort" ... a different definition based on the audience. The GX is a truck based platform ... so will never provide a sedan (pretend SUV) ride no matter the tires, tire pressure or shocks ... or whatever modification. If you understand this and are realistic ... there are modifications that are available ... but the first step is for you to better define exactly what you are trying to accomplish beyond "fixing the harsh ride".

Focus on the shocks ... the stock OEM shocks (KYB or Tokico) are not that great when compared to alternatives that better respond to road conditions while minimizing translation into the chassis.

For primarily street use, my recommendation ... Bilstein 4600's / Front PN = 24-187541 / Rear PN = 24-187558 ... these are direct OEM replacements and will result in a more controlled ride ... reduced brake dive, reduced lean in corners, reduced translation into the chassis, reduced shock "nervousness" and improved tracking.