In priority order:
Decent seating. It is called a lounge after all and many airports are now using minimal cleaning metal seating at the gates, so something comfortable in the lounge is an improvement.
Boarding calls. Monitors can’t be everywhere and I hate having to get up every few minutes to check my flight status as boarding time approaches, in lounges with no calls.
Wifi access. Preferably maintained by professionals or at least someone who knows more than just where the on/off switch is, so that not all of the traffic can be monitored by the Chinese and Russian governments.
A decent mix of healthy, comfort, savoury and sweet food options.
Staff to clear away used items and utensils, commensurate with the number of lounge users.
Clean bathrooms and showers.
Barista or brewed coffee, tea and hot chocolate.
Service desks. Staffed by knowledgeable personnel with sufficient authority to make necessary changes during irrops.
Natural lighting, preferably with runway/tarmac views.
Someone patrolling the lounge with a large rattan cane as usually seen being wielded by street police in India. To enforce peace and quiet on those having loud conversations on their phone, or watching tv shows/movies on devices and not using headphones! Or putting their shoes or feet up on the furniture. (this suggestion is TIC… a bit…)
Things I couldn’t care less about:
Alcohol
Objects d’art
Other peoples clothing
Basically, TK lounge Istanbul, everywhere.
Or Air NZ lounges; they seem to do everything right, even the little regional ones!