Toradora!, B-gata H-kei Recommendations
Extremely similar main female characters, as Taiga and Yamada had the same personality, minus Yamada's sex-centered thoughts. Both had very good comedy, with BGHK winning, but Toradora had more depth in its supporting characters. Regardless, if you liked one, you will like the other.
Somehow I felt that these two series were almost similar, except that B Gata H Kei has more sex-related subjects.
Both of them have a main female character that deny their love for the main male character, they got friends to help them out and they both share the comedy and romance genre.