Ranma ½, Urusei Yatsura Recommendations
Both are comedy mangas created by Rumiko Takahashi, so the style and character design are very similar. The romance is also a strong element in both - though it's shown in a comedic way. Some ideas in Urusei Yatsura were later used in Ranma - Ranma and his father's relationship is clearly modelled after Ryuunosuke and her father's one and so on. All in all, if you read one of these mangas and liked it, you would definitely enjoy the other one too.