Depends on the airport
Absolutely second the advice of the poster who advised buying the secondary insurance.
Dozens of trips to Germany. Consistently get screwed in Frankfurt with bogus damage claims. Munich ok. Stuttgart is amazing... fast, clean cars and no B.S.
London OK, get screwed in Paris. Go figure.
Worst place in USA has got to be Los Angeles International. All the car lots are off-airport in an area that reminds me of some interesting times I had in Iraq. Having waited forever for a bus while inhaling clouds of diesel smoke, you are taken on a torturous route to the lots. Thoroughly disoriented and delayed 30-60min you are now a captive customer in the agency's filthy facility. Wait another hour and they figure you will sign damn near anything. And why not? Unless you reverse the process through the shuttles or take an exciting walk through Hawthorn - at night perhaps - for an identical shakedown at a competitor's site. This is an freakin' organized crime racket!
If you've got to go to LA, fly in through John Wayne instead. If coming from abroad you will have to do a connection somewhere but time-wise probably come out ahead regardless. And you won't get shaken down, mugged, etc