I have gone higher, but I now limit myself to 45# on the barbell when I have to heft it onto my shoulders (I add up to 20# additional pounds using a weight vest). My shoulders--the limiting factors-- thank me for it!
If I want to go heavier than 65# total, I'll use my Soloflex Rockit, a squat/leg press machine that I've done up to 210# on (but it's been gathering dust for a while, because I've been doing more endurance lower body work)
When doing deadlifts, I have gone up to 65#.