Which would be safer

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I don't believe one is safer than the other. You could go with either one. You will always have a large voltage referenced to neutral/ground at the 1k resistor

First, I would use a step-down transformer

It can be done safely. Put some rubber glove on.

I think the first circuit is more safe...

Both circuits are equaly unsafe, cuz output voltage to ground is 85V peak! Every voltage above 42V is dangerous. It won't kill you directly, but it could shock you and you might "falling from a ladder", or whatever you can imagine ... And don't even think about over voltage damage to the resistors. Voltage at mains can have high spikes! There are good reason to buildin protecting mechanism against over voltage. There is no way around to use a galvanic separation (transformer) to be on the safe side. Anyway, the circuits just give <90uW what can you drive with such a low power?

Yes hurz is right. Nothing is safe, when working directly from mains. It's not 170V. It's not even 230V, as many tend to believe. The peak is at 320V, and sometimes when electrical noise gets into the mains, it can peak even higher. The safest way is to use galvanic separation (a transformer). Another cheap way is to use a capacitor, as a current limiting device, but since the mains is not a perfect sinewave, it may have some higher harmonics, that will pass much stronger through the cap. Not to mention the inefficiency of these methods. Sometimes the efficiency may fall to less than 10%, while most transformers maintain efficiency beyond 80% (some of them above 95%).

H

I use a 6V plug pack with the rectifier pulled out. it swings about 9Vp-p up to about 100mA before a PTC kicks in