Harry designed Meghan's ring and it looks fine to me. Plus it has romantic and sentimental meaning, what with the two smaller stones having belonged to Diana, and the large center stone being sourced from Botswana where Harry and Meghan bonded in August 2016.
We don't see good views of Margaret's and the Queen Mother's rings. They seem similar, and rather old-fashioned, unsurprisingly. Wallis' huge square-cut emerald is over-large, old-fashioned and gaudy. Princess Anne's two rings are similar in design with different colored stones. I like the second one best between the two.
Camilla's ring is rather large and a bit ostentatious. Zara's ring is simple, elegant and very pretty. Fergie's ring has an interesting starburst design, but the look of it is a bit unusual for an engagement ring. Eugenie's ring has a similar colored stone to Fergie's, but it's softer in color and the design is more compact. It seems to suit Eugenie very well. The Queen's ring is classic diamonds which never go out of style. The Queen's ring is similar to Sophie's, Autumn's, Bea's, and somewhat similar to Meghan's because they are all made of diamonds. Of the diamond rings, I like Bea's, the Queen's and Meghan's the most.
Out of all, I think Bea's, Eugenie's and Meghan's rings have the most romantic and appealing designs but that's because they are the most up-to-date and I know more of the story behind them. If I had to pick one, I might pick Eugenie's, but I love the diamond rings. I think Bea's design is so cool and classy. It seems perfect for her, just as Eugenie's seems perfect for her, and Meghan's seems perfect for her. It made sense for Meghan to switch out the gold band on her engagement ring for a thin diamond band since she often wears it with her gold band wedding ring.
When Meghan wore Diana's gorgeous aquamarine ring to her wedding reception as a wedding gift from Harry, it was so to-die-for. Many knock-offs of Meghan's engagement ring and the aquamarine ring have been made since then.
For me personally, my tastes would go toward an engagement ring made of diamonds and aquamarine, like these:
https://www.brilliantearth.com/Aqua...=4580153131164440&utm_content=Aquamarine PLAs
https://www.brilliantearth.com/Aqua...=4580153131164440&utm_content=Aquamarine PLAs
Oh and Kate's ring, while it surely has a lot of special significance since it was Diana's and the history is iconic, it does not represent a happy union between Charles and Diana. But then we could view it as representing the polar opposite blessing for Wm & Kate. I like the color of the stone, but it is old-fashioned in its design, and thus for me it suffers in comparison with most of the other rings.