I've 1 shotted only a few tanks... but all of the french tds are on the list for me. That and all the german mediums.
I actually don't mind gold rounds all that much, minus the derp HEAT rounds because those are just ridiculous. I've tried out some gold rounds myself and they aren't auto-pens on a lot of tanks... you still need to aim GENERALLY in the weak spot. Like you still can't pen the T-29/30/32/34's front easily with same tier gold rounds, you can't pen the E-75's upper glacis or the turret, etc. It's also a good equalizer... with gold rounds, my m7 can actually pen bigger tanks it regularly gets matched up against. So skill comes into play once again and I can actually outfight some bigger tanks like KV3s and whatnot if their driver sucks.
Like yesterday, me and my friend were fighting an IS6 with our SU-122-44s. Rest of the team was folding quickly and we were at risk of being flanked by an IS-3 and a tiger P. So I said "fuck it, loading some gold rounds" to try to take out the IS6 quickly. Long story short: bounced 2 gold rounds in a row on the IS6's frontal glacis (tried to hit the hatch), and switched to regular AP and resorted to aiming at the tiny strip of lower glacis once again. The whole stunt left me exposed for 2 more shots that I luckily ate. In retrospect, if I had actually AIMED properly (like I normally do) instead of trying to derp with gold rounds , that IS6 would've been dead and I would've only taken 1 shot instead of 3.