Over the past two years and many, many road trips, I've been lucky enough to drive several different rental cars. Lucky because it's sort of like being able to take the car on an extended test drive. Sure, a trip around the block is fun, but it doesn't really tell you a lot about fuel consumption, or uphill acceleration, or how conveniently located all the knobs and switches are.
So far, the worst car I've driven has been the Pontiac Grand Am. Twice, I've had this kind of car, and both times I've found the seats to be uncomfortable and the dashboards confusing. I can't remember if this was a problem the first time I drove one, but the last time I drove a Grand Am (on the trip to Manitoulin), there was no cruise control (which sucks). Also, the cupholders were poorly placed, the steering wheel didn't tilt back far enough, and acceleration was sluggish.
I liked the Nissan Altimas - good design, roomy, generally nice rides. The first time I drove one, way back on my very first road trip, I ended up parked beside an Altima which was identically to the one I was driving, except for the license plate, at a hotel. I walked out the next morning and had no clue which one was mine.
This trip, I have a Seabring, which I'm loving; while I doubt I'd own one myself, this one is lovely. Lots of room, clean dashboard, and superior acceleration, even on hills. The sound system is nice, too.
(Which brings me to one of my favourite/most annoying features - the automatic volume adjust. This is the feature where the volume of the radio adjusts to how fast you're driving. If you're driving down a city street, it's normal, and if you're driving down the highway it gets louder to compensate for the sound of the wind and engine. I loved this feature, and have only had it on one or two cars; however, I sometimes find it annoying because you keep having to adjust the volume manually if there's heavy traffic and it's stop-and-go.)*
* Oh lord, this just won the "most boring post ever" contest on my blog. Clearly, I need to write about something else. Give me a sec...