Question - what gas, if any, do you use when bottling?

I have bottled with no gassing (displacing air in the bottle with some
inert gas), and have used CO2. The latter introduces a soluble gas that
invariably dissolves to some degree, creating a mild out-gassing on
opening. No good. Not gassing the bottle at all is an option (and what I have
been doing for the most part), but I'd like to try to minimize air on
my better wines - and am considering argon (density, less soluble).
Any experiences out there?

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