I really loved Prince turns into Frog, it was hilarious, amazing music, and I loved the chemistry (although, I get how that can be seen as a carbon copy, from the amnesia aspect). Silence is another one of my unforgettable Tw-dramas that deals with sign language and deafness that stood out for me. This one isn't the type to watch if you're looking for comedy, but just a beautiful, heart wrenching story. The Magicians of Love has this plot point of a fountain with stones, and if you meet each other, it means you're meant to be. I really loved that aspect. It was really nice. But the serie does seem to get really draggy..
I feel bad I haven't watched as many tw-dramas these days, so I don't have many recommendations for you, because I'm so into k-dramas. If I do watch tw-dramas, I usually re-watch old favourites x_x. But I'd have to agree to the ones mentioned above:
+ In Time With You
+ Fated to Love You (this reminds me so much of Prince turns into Frog, it has a lot of the same aspects, comedy, chemistry, and beautiful story line)
+ Autumn Concerto (this one is really a beautiful story, won't have much humor, and has a lot of gut wrenching feelings)
+ My Queen (Hilarious, great chemistry, and I loved the story. I personally prefer the k-drama version, but this one was beautiful)
If I had to pick 1 drama I'd recommend, it would be In Time With You (as you can probably tell from my username haha), but you've already seen it. The next one I'd recommend is Fated to Love You. It has so many different qualities in it that would appeal to a viewer, as well as being not as dated like the rest of my favourites.
If I had to sort them by favourism, it would go by:
In Time With You
Prince Turns into Frog
Silence
Fated to Love You
Autumn Concerto
The Magicians in Love
My Queen
And as you could probably tell, most of these actors are in similar dramas I loved. That's how much I love their acting. I do realize a lot of these are kind of dated, but I really don't know many amazing ones that are not dated at this present time. I hope this helped you out a little bit. ^_^