...would greatly appreciate car rental companies located at the Lisbon airport. Many thanks in advance! (the newest recommendation I found in the archives was from Dec. '22)
All the major companies are there, so it comes down to your preference. They all show up on Google maps.
We usually use an aggregator
https://www.autoeurope.com/
and choose from their offers.
For us the key is to purchase the full insurance from the car rental agency itself ( not from the aggregator or any other third party), to avoid damage charges weeks later after returning the car - it's a common practice in Portugal.
Compare zestcarrental.com.