We are visiting Maui, Kauai, and Honolulu this summer. Any suggestions about the best car rental places? I'd prefer to not have long lines and hassles if that's possible. Thanks.

you really have to check them all. sometimes hit a good deal from one of them. if you have airmilage links to rental cars can sometimes find good deals

We've had good luck with Avis and National. Spouses are free additional drivers with Avis which is nice.

I have been checking prices for our upcoming July trip to Kaua`i and Alamo had the best deal on a convertible for 2 weeks. Alamo had a special (6T) last summer so I am planning on waiting to see what comes up.
In Kaua`i the rental car process is usually very easy and quick with not a lot of waiting involved.
-Bill

I am absolutely not an expert but just returned from Honolulu and saw local car rental places all over w/ deals posted. No lines, no waiting, extremely low key (i.e., parking lot with shack where you paid $87/wk, $21 1st day of 3 day rental like that).

But if you're going to have a car the whole time, I'd probably rent out at the airport even if it cost a bit more to save the hassle of a bus, shuttle, or taxi to town/hotel (Maui and Honolulu, never been to Kauai).