I'm looking for some new Manga to read, and my own searches are turning up fruitless. I've read a bunch of manga, so a lot of your suggestions won't be any help. but ya never know  😛  

So what I'm NOT looking for is:  
Action  
Shounen(Unless it's a good romance that I cant pass up)  
Shoujo or Josei that has that weird shoujo art with the strangly tall disproportionate guys with weird long fingers (You know what I'm talking about), which is somehow supposed to be attractive (It's not) but other than that shoujo and Josei is fine  
Manga that is purely Hentai or NTR, but some adult scenes are fine, as long as it's not the main focus of the manga  
Manga where the Mc's relationship does not progress fast enough  

EDIT: I forgot to add that I also try to stay away from fantasy, sci-fi, or Extremely plot driven romances

Things I DO want  
Cute, or funny relationships, but not too pure like Hibi chouchu or something  
Age gaps, Older M or F doesn't matter  
Sadistic partners  
Tsundere partners  
I'm also looking for some good yaoi or shounen ai, however I don't want to read something that has too much H scenes that Yaoi seems to do, nothing too smutty, plus I hate it when all the other characters just play along, like they live in a world where everyone they know is also gay, like I want there to be some kind of struggle with their relationship  
Gender Bender/Trap manga, such as Boy Skirt (The ending sucked though)or Prunus Girl Which by the way is really good for a Gender Bender  
I also enjoy Yuri, but I'm pretty sure I've read all the good yuri (There's not much) Such as Octave, Girlfriends, Prism, Lily Love  
Seinens/Shounens like bonnouji, comic studio, and a few others are good too

Too sum it all up, I just love all kinds of romance. especially of it's really good  
I could not provide a list of all I have read, but any suggestions are welcome  
 

Sensei Lock On!: Comedy, Older Female, Romance focus
Spirit Circle: Plot driven, Decent amount of romance
ReLIFE: Comedy, Romance
Ran to Haiiro no Sekai: Supernatural, Slice of Life, Decent Romance, Older male
Otoko no Isshou: Older male, Slice of life
Ojojojo: Comedy, Romance, SoL
Karei Naru Shokutaku: Cooking, Romance, Older male, Comedy
Gisèle Alain: Romance, Older male, SoL
Futari no Renai Shoka: Older female, SoL, Romance
Boku Girl: Gender Bender, Comedy, School Life, Supernatural
Balance Policy: Gender Bender, Romance, Sci-fi
Arte: Historical, Romance, Older male
American Ghost Jack: Horror, Romance, Supernatural
Ii Orc no Hi: Comedy, Romance
Marie no Kanaderu Ongaku: Sci-fi, Romance, Fantasy
Miman Renai: Older male, Comedy, SoL
Himitsu no Akuma-chan: Trap, Romance, Shounen ai, Comedy
Nozomu Nozomi: Gender Bender, Romance, Comedy
Ore ga Akuma de, Aitsu ga Yome de.: Older male, Romance, Supernatural
Sekainohate de Aimashou: Gender Bender, Romance, Fantasy
Shinshi na Meets Girl: Older male, Some Romance, Comedy
Sore wa Totsuzen, Unmei no Aite ga: Comedy, Romance, School Life, Tsundere
Sukimasuki: Comedy, Romance
Usotsuki Mi-kun to Kowareta Ma-chan - Totteoki no Uso: Plot Driven, Some Romance, Yandere
Sundome: Sadist, Romance, Drama
Yasashii Sekai no Tsukurikata: Romance, Comedy, School Life
Shigeshoushi: Some Romance, Older male, Slice of Life
Demi-chan wa Kataritai: School Life, Romance, Older male, Comedy
3-gatsu no Lion: Romance, SoL, Sports (Shogi)

I don't read too many romance driven series, so I merely went through my list to try and pick memorable series that generally fit what you asked. Since you have no public lists I just gave a swath of series.

Thanks for the list, I picked out a few good ones, Most seem pretty good, though some I've either already read, or didn't look interesting. I just signed up to the site to ask a question 😛 , although I've been using it for awhile just for the search engine, which is pretty decent.