Best cable connection for 2ch speakers?

When you say "analog," I'm assuming you mean an analog source like a record player or analog tape. If you mean which way to connect a CD player to a line stage, it depends on how good the player's built-in DAC is compared to an external DAC or built into a pre/pro.

I like analog for 2-channel. IMO analog provides more low level resolution and better phase relationships, creating a lush soundstage from 2 channels. I think one reason surround took off with digital is because 2-channel digital is a bit threadbare by comparison. Surround sound in the analog era (quadraphonic of the mid-'70s) was a bust, probably because most people got plenty of musical satisfaction from regular stereo.

I'm sure there are A-goners with high res. 2-channel digital systems, but if you look at how the market has voted with its wallet over the decades, it's 2-channel for analog, multi-channel for digital.