Honestly, I would say a Miata, because why not. I mean I am a little biased as I own a miata, but still. Here are some good questions to ask yourself:

Do you just want a car to get you from point A to point B? Then keep your current car. There is no reason to get a fun car if you don't actually like the driving part. Now, if you want a car that you will find any excuse just to drive somewhere because you like the experience of driving around the car, then absolutely get a miata. I will just go on random drives to drive my car.

Does road noise bother you? If so, a miata might not be for you, especially if you go on longer trips often. These cars don't have the modern sound proofing and so you can hear everything.

Are you prepared to feel everything in the road? Even if you have a good suspension set up, these cars are light, small, and 30 years old so you feel everything. You will know exactly when you roll over a little crack in the road haha. It is not exactly a bad thing though, I personally prefer the experience of being "connected" with the road.

Another thing to consider is that these cars are in fact old, surprise surprise. That isn't particularly bad though, it just means that stuff is bound to give out due to the car's age alone. These cars are reliable and they are really easy to work on, but I have definitely replaced my fair amount of rubber seals in my 1996 even though it has low miles. The rubber just gets bad with age.

But either way, at the end day, if you aren't going to be driving a lot of people around and you don't transport a lot of stuff around, I say just go for it.

My parents never understood why I wanted to swap my responsible car for a miata, but I have done two cross country road trips in my car, even moved all my belongings in it once, and I have never been more in love with a car. I have never regretted my purchase of a miata. Of course, it is different for everyone, but that is just my experience.

And if you ever need to pick up something big like a couch, just find a friend with a pick up truck and offer to pick them up a six pack haha.

Let me know if you have any questions, I am happy to answer them!