I'll see if I can remember all the rentals I have driven, some of them I only rode in them.
Impressed:
2000 or 2001 Ford Focus: It was a base model with manual windows, locks and mirror. Also had am/fm/cassette. This was the first rental car as far back as I can remember. Being used to riding midsize to larger cars it did feel a bit crammed but got used to it quickly. Good visibility, responsive, good interior. Really considered buying this car.
2000-2005 Dodge Neon: Everything felt very balanced and just about right. Smooth engine response, relatively quiet interior, and good visibility. The gas pedal is kind of stiff compared to other cars I've driven. I remember my dads old Dodge Caravan was the same. The mirrors were a tad small.
2005 or 2006 Chrysler Town & Country: This was probably the longest time I have been in a rental vehicle, used for a long trip. Has decent seat room, entry/exit for rear bench a bit of hassle. Quiet engine with decent power but transmission doesn't shift as well as I like it. Good fuel economy considering the car was fully loaded with passengers and luggage, ~23-24mpg according to the display.
Not really as impressed:
2002 or 2003 Mazda Protege: It looks like a okay car from the outside but I just didn't like the driving feel. It felt very disconnected. Engine didn't sound that refined, somewhat noisy at higher rpm. Steering felt very loose. It was probably the base model, something interesting I remember only the driver side had the power door and/or window lock control. Interior quality seems like it could be better. Overall just getting from point A to point B is okay. I did like the gauge layout though. Fuel economy was okay for its size.
2002 or 2003 Mitsubishi Galant: I didn't really like the looks of the car, interior was okay. Engine response felt a bit of lag and felt underpowered for this car. Just didn't feel very connected when driving, felt like floating. So-so fuel economy.
2000-2003 Dodge Ram van 3500: Another vehicle I have spend a lot of time in for road trip, had a lot of people go on the road trip. Rear seat entry/exit a bit of squeeze as there is only one set of double doors for the rear. Have to be careful when opening side doors not to hit another car parked next to you, sliding door would probably be better. Ride felt very jumpy and didn't feel that stable. Plenty of power but of course fuel economy was not great. I wouldn't choose a van this large for long trips, a Dodge Caravan would be better choice in my opinion.