So I'm in the same boat as you and am getting into Tales for the first time this year. Well, I did play Zesteria for like an hour in 2015 and didn't like it, but that doesn't really count. So I picked the three that I'm most interested in to start with:
1. Phantasia, which I'm playing now because it's the first game in the series. I want to see where it all started, and I've heard the Super Famicom fan translation is iconic. I like it so far. Lots of attention to detail for its time with the NPCs, and the 2D combat is unique and fun.
2. Symphonia. The one everyone talks about, and it's co-op, which is rare for RPGs, so my girlfriend and I are going to play it together when I finish Phantasia and she finishes Vesperia.
3. Arise. A lot of people claimed that Final Fantasy XVI was just a ripoff of Tales of Arise with a Game of Thrones coat of paint. So I might as well just play Arise instead of XVI since I'm falling out of love with modern Final Fantasy and the story sounds really interesting.
I was also thinking this would give me a good vertical slice of classic Tales, the Golden Age of the series, and then the modern era. From there, I can decide where to go next based on what I enjoyed most. Of course, having no personal experience with the franchise, I'm not 100% sure whether this would be the optimal experience.