I have a 95 ES300 with 108,000 on it. I personally think the ride could be better. When I am on the freeway and hit a bump, crack, etc... I seem to here a pretty loud klunk. I can't tell, but i think the shocks may be originals (they're not leaking). However, the ride is perfect and it handles quite well on decent pavement/asphalt.

I always thought that to test your shocks to see if there worn is to physically push down hard a couple times on the front/rear of the vehicle and it should stop itself after 1-1.5 bounces. My car will do this. Are there any bushings that could go bad?? Maybe it's just me and the car is fine and I'm being picky--
Also, New shocks KYB?? or Sensa-Trac's????

 

At 108k, your shocks are gone. No opinions as to replacements, since we no longer have an ES. But it's almost certain shocks. As far as whether or not they are original, IF the services were all done at Lexus, they'll have a complete record of every service done, regardless of owner.