No Golden Time or Toradora! or Pet Girl of Sakurasou or Ano Natsu de Matteru? You left off almost all my favorite shows and your #5 was painful to watch. It's like a chain of unrequited love. I made it to the time jump and nobody on that show up to that point actually liked anybody else that was into them. Everybody liked a person that was into someone else.
AO was decent but if you compare it to the original it's trash and just a head's up the ending has ZERO closure.
No GT, Pet Girl or Ano Natsu didn't consider them to be anything over a 8/10. Very good though. Have you seen Nodame and Spice & Wolf? I understand the gripes with Inuyasha but the romance was Rumiko Takahashi at her finest, particularly if you understand Kikyo's character and have seen the continuation not just stopping at the original.
Unrequited love that has potential to develop into reciprocated feelings is a pretty important dramatic element of romance so I didn't mind it in Nagi no Asakura. nor do I dislike slow progressing romances if the plot is there and a non generic, powerful theme is being utilized which it was in racism/discrimination between the land & sea dwelers. Never before had I seen that intertwined into the story of a romantic anime before. Animation is probably the best I've seen in a non movie, OST's were gripping and overall I found it to be a great anime that gave you more than just romance and introduced real world obstacles that added great drama to the circumstances. To each their own but I found it to be brilliant, don't understand the painful to watch sentiment. Star Driver, Ladies & Butlers were painful to watch
Tora Dora was outstanding, but I'm gonna put it behind those five. I just tend to favor romances with another element besides just love and comedy. Something extra that can help accentuate that drama and keep me thinking. Everything in my top 5 has this and I'd probably put Honey & Clover before it too
continuing those rankings
6. Honey & Clover
7. Your Lie in April
8. Tora Dora
9. Ef. Tale of Memories
10. Anohana
And there's a good chunk of quality series that are either manga/novel exclusive or the anime doesn't have enough seasons to cover the source material. If that wasn't an anime only list then HakoMari, Ouran High School Host Club, Fruits Basket, Dengeki Daisy, Nozoki Ana, Velvet Kiss, Sundome, Special A, Suzuka, Onani Master Kurosawa, Our Happy Hours so on and so forth would be up there. Need to rewatch Clannad before ranking as I've forgotten much of it aside from the obvious parts & five centimeters per second is on my plan to watch list